AN INVESTIGATION OF GADOLINIUM MIXED HALIDES MICHIGAN STATE UNIVERSITY Thesis for the. Degree of M. S. LAURA R. SEIDEMANN 1976 —_— I I 7) T‘ R 3" N11»; g itiltc University 1 a . u .n; Hal. an. AEJQ ”nu-In mixec ABSTRACT AN INVESTIGATION OF GADOLINIUM MIXED HALIDES By Laura R. Seidemann A series of gadolinium mixed halides has been prepared. The mixed halides were prepared by: (I) seaIing in an ampouIe a I:0.5:n_(where g.= 3.5 and 4) moIar ratio of GdzHgC12:HgI2 and heating in a furnace overnight at 300°C, with subsequent suinmation of the mercury contaminants and, (2) heating a GdCT3 + GdI3 meIt. The far-infrared and X—ray powder diffraction data indicated that as the temperature is raised the composition of the sampIe changes. The product formed from the moIar ratio I:0.5:4 produces a subTimate - which appears to have a constant composition regardTess of the temperature of suinmation. The far-infrared spectra of both GdCT3 and GdI3 are reported together with those of the mixed haTides. .31 .. ,l. «amalgamatiwiufié? AN INVESTIGATION OF GADOLINIUM MIXED HALIDES By . )3“ Laura R. Seidemann A THESIS Submitted to Michigan State University in partiaI fquiIIment of the requirements for the degree of MASTER OF SCIENCE Department of Chemistry I976 The Harry A. througho Spe their di proofree Th. Tempera to heIp Th Commiss acknowi ACKNONEEDGMENTS The author wishes to express her sincere gratitude to Professor Harry A. Eick for his guidance, encouragement, and assistance throughout the course of this research. Special thanks are given to Tad Quayle and Leon Halloran for their discussions, support and for their expenditure of time in proofreading this thesis. The assistance of the past and present members of the High Temperature Group for their fruitful discussions and willingness to help is greatly appreciated. The financial support of the United States Atomic Energy Commission under contract number E2 (ll-l)-7l6 is gratefully acknowledged. ii 34.. Chapter I II III TABLE OF CONTENTS Chapter Page I INTRODUCTION ..................... I II BACKGROUND AND THEORETICAL CONSIDERATIONS ...... 7 PREPARATION OF ANHYDROUS LANTHANIDE HALIDES ..... 8 STRUCTURAL INFORMATION ................ 9 THE APPLICATION OF FAR INFRARED SPECTROSCOPY ..... lO POTENTIOMETRIC DETERMINATION OF CHLORIDE AND IODIDE ...................... l2 SOLID SOLUTIONS ................... l2 III EXPERIMENTAL MATERIALS, EQUIPMENT AND PROCEDURES. . . l5 CHEMICALS ...................... l6 MATERIALS ...................... l6 PREPARATIVE PROCEDURES AND EQUIPMENT ......... l6 Anhydrous Lanthanide(III) Chlorides ....... l6 A. Taylor-Carter Procedure ........... l7 B. Carter-Murray Procedure ........... l7 Anhydrous Lanthanide(III) Iodides ........ 20 Lanthanide(III) Mixed Halides .......... 20 A. Pseudo Carter-Murray Procedure ........ 20 B. GdI3 + GdCl3 Melt .............. 22 Storage of Samples ................ 23 Chapter Chapter Page ELEMENTAL ANALYSIS .................. 23 Qualitative Analysis Procedures ......... - 23 A. Detection of Iodine ............. 23 8. Detection of Chlorine ............ 23 C. Test for Mercury ......... i ...... 24 Quantitative Analysis Procedures ......... 24 A. Potentiometric Determination of Chloride and Iodide .................. 24 B. Gravimetric Analysis of Gadolinium ...... 27 C. Data Analysis of Gadolinium ......... 27 l. Potentiometric Titration ......... 27 2. Gravimetric Analysis ........... 29 X-RAY POWDER DIFFRACTION ANALYSIS .......... 29 INFRARED SPECTRA ................... 29 IV RESULTS ....................... 30 ANHYDROUS GADOLINIUM TRICHLORIDE ........... 3l ANHYDROUS GADOLINIUM TRIIODIDE ............ 3l GADOLINIUM MIXED HALIDES ............... 3l Pseudo Carter-Murray Procedure .......... 3l A. Initial Investigations ............ 3l B. The Molar Ratio, HglzzGdzHgCl2 = 3.5:l.0:0.5. 34 C. The Molar Ratio, HglzzGdzHgCl2 = 4.0:l.0:0.5. 37 l. Heating l ................ 37 2. Heating 2 ................ 37 3. Heating 3 ................ 39 4. Heating 4 ................ 41 iv Chapter VI APPEN REFER Chapter Page GdCl + GdI Melt ............... 44 3 3 EVIDENCE OF GLOVE BOX CONTAMINATION ........ 44 V DISCUSSION ..................... 48 FAR-INFRARED ANALYSIS OF GdCI3 AND GdI3 ...... 49 INITIAL INVESTIGATIONS ............... 49 THE MOLAR RATIO HgIz:Gd = 4.0 ........... 50 THE MOLAR RATIO HgIzzGd = 3.5 ........... 55 SOLID SOLUTION ................... 55 VI CONCLUSIONS AND SUGGESTIONS FOR FURTHER RESEARCH. . 56 APPENDICES ........................ 58 REFERENCES ........................ 78 Table Ur La St! Ana Ana Ana Ana SUI Table 0501-900 LIST OF TABLES Page Uranium Mixed Halides .................. 3 Lattice Parameters of MFX Compounds With the PbFCl Structure Type ...................... 5 Structural Types Reported For Lanthanide Halides ..... l0 Analysis of Heating l (GdI3_xClx) ............ 37 Analysis of Residue of Heating 2 ............. 39 Analysis of Residue and Sublimate of Heating 3 ...... 4l Analysis of Sublimate of Heating 4 ............ 44 Summary of Empirical Formulas .............. 53 vi Figure TO I Figure 10 11 12 LIST OF FIGURES Drawing apparatus used for the preparation of GdCl3 . . High vacuum apparatus used for sublimation of the anhydrous trihalides .................. The reaction proceeds in a quartz ampoule which is situated in a furnace overnight at 300°C ........ Apparatus used for the potentiometric determination of chloride and iodide .................. Plot of potential y§_volume of titrant added for the. titration of chloride and iodide ............ Far infrared spectrum of GdCl3 ............. Far infrared Spectrum of GdI3 ............. Far infrared spectrum of the product prepared at 450°C from the molar ratio, HglzzGdzHgCl2 = 5.6:l:0.5 . . . . Far infrared spectrum of product prepared at 500°C from the molar ratio, HglzzGdzHgCl2 = 3.5:l:0.5 . . . . Far infrared spectrum of the product prepared at 450°C from the molar ratio, HgI2:Gd:HgC12 = 4.0:l:0.5 . . . . Far infrared spectrum of the residue prepared at 550°C. Far infrared spectrum of the residue prepared at 600°C. vii Page l8 19 21 26 28 32 33 35 36 38 40 42 15 _Figure Page 13 Far infrared spectrum of the sublimate prepared at 600°C .......... . ............... 43 T4 Far infrared spectrum of the sublimate prepared at ' 700°C ......................... 45 l5 Far infrared spectrum of the residue prepared at 700°C. 46 viii Appendix A LIST OF APPENDICES Appendix Page A Observed sinze (A = l.5405l A) and Interplanar d-Values for GdCl3 .................. 58 B Calculated sinze (A = l.5405l A) and Interplanar d-Values for GdCl3 .................. 59 0 Observed sinze (A = 1.54051 3) and Interplanar d-Values for GdI3 .................. 61 D Ca1culated sinze (A = l.5405l A) and Interplanar d-Values for GdI3 .................. 62 E Observed sinze (A = l.54051 A) and Interplanar d-Values for the Product Produced at 500°C for the Molar Ratio HgIzzGd = 3.5 .............. 64 F Observed sinze (A = l.5405l A) and Interplanar d-Values for the Product Prepared at 450°C ...... 65 G Observed sinze (A = l.5405l A) and Interplanar d-Values for the Residue Produced at 550°C ...... 67 H Observed sin20(A = l.5405l A) and Interplanar d-Values for the Sublimate Produced at 550°C ..... 68 I Observed sin20 (A = 1.54051 3) and Interplanar d-Values for the Residue Produced at 600°C ...... 69 ix Appendix J Observed d-Values Observed d-Values Observed d-Values Observed d-Values Melt ......................... Observed d-Values Observed d-Values Observed d—Values 2 sin 0 (A = l.54051 .A) and Interplanar for the Sublimate Produced at 600°C. . 2 sin 6 (A = 1.54051 .A) and Interplanar for the Residue Produced at 700°C. . . 2 sin 6 (A = l.54051 A) and Interplanar for the SubTimate Produced at 700°C. . 2 sin 0(A = 1.54051 A) and Interplanar for the Product Produced From the GdI3 2 sin e (A = l.5405l A) and Interplanar for GdOCI ............... 2 sin e (A = l.54051 A) and Interplanar for GdC13~nH20 ............ 2 sin 6 (A = 1.5405l A ) and Interplanar for GdI -nH 0 ............. 3 2 Page 70 71 72 + GdCl3 73 74 75 76 ‘I‘IIIII 4; . gaigififinrdzfiga CHAPTER I INTRODUCTION -’---m— _. _. —— ~_’~—_— INTRODU” 1r, mixed ha and flu: along w‘ time. S were rep sized, a EuFIg an haIide I structur. The to resuI‘ structure such tha: Others, 1 Accc "0t work methods u either tr atomic no at high t thErmal d halide Or the initi In additi DFOpertje INTRODUCTION The literature abounds with reports of divalent and trivalent mixed halides. Early work on alkaline earth fluoride-chlorides and fluoride-bromides dates back to the 1890s.1 Lead mixed halides, along with those of other Group 4 metals,have been known for some time. Several mixed halides of trivalent and tetravalent uranium 2,3 4-6 were reported in the late 19505. In 1973, EuFCl was synthe- sized, and shortly thereafter, EuFBr was prepared,8 followed by 10 EuFI9 and EuClBr. Until recently, no trivalent lanthanide mixed halide has been reported, but Haschke7 predicted on the basis of structural relationships that such phases should exist. The reported mixed halides of uranium, Table l, are thought to result from the formation of solid solutions. The crystal structures of the trivalent and tetravalent uranium halides are such that it is possible to substitute certain halogen atoms for others, thus yielding a wide range of stable compositions. According to the reports, halogen displacement reactions will not work for the preparation of any uranium(III) mixed halide. The methods used for the preparation of uranium(IV) mixed halides either treat the trivalent uranium halide with a halogen of higher atomic number or allow two different tetravalent halides to react at high temperatures. The uranium(III) halides can be prepared by thermal decomposition or hydrogen reduction of a mixed uranium(IV) halide or by fusion of two trivalent halides. No work other than the initial characterization of these compounds has been reported. In addition, very little is known about their physical and chemical properties. Table 1. Uraniuml Uraniur Table 1. Uranium Mixed Halides3 Compound Preparation Uranium(III) UClZBr 2UC13 + UBr3 (fusion) UCIBr‘2 UCTBr3 + H2 UCTZI UC12I2 + UCTZI + 1/212 UCII2 UC13 + 2UI3 (fusion) UBrZI UBr212 + UBrZI + 1/212 UBrI2 UBr‘I3 + UBT‘I2 + I/ZI2 Uranium(IV) UF3C1 UF3 + 1/2C12 (310°) UFZCTZ UOZF2 + 2CC14 (450°) UF3Br UF3 + T/ZBrZ (250°) UF3I UF3 + 1/212 (250°) UC13Br UCT3 + 1/ZBr2 (500 ) UCTZBr2 UCl4 + UBr4 (fusion) UClBr3 UCl4 + 3UBr4 (fusion) UC13I UCT3 + 1/212 (500 ) UClZI2 UCl4 + UI4 (fusion) UClI3 UCl4 + 3UI4 (fusion) UBr3I UBr3 + 1/212 (500 ) UBrZI2 UBr4 + UI4 (fusion) UBrI3 UBr4 + 3UI4 (fusion) I I 1 1 1 Twc been re; the dehy and (2) Eu(II) r halides (Table structu and fou halides coordir the flu coordir visuali have be Tw These a to prep I:I.25 excess Consist The uni to be 01 L=9.12 solved t Two different methods for preparing EuFX (X = Cl, Br, I) have been reported. The preparatory schemes involved (1) reaction of the dehydrated Eu(II) halide with the corresponding fluoride, and (2) fluorination of the appropriate dihalide with Man. These Eu(II) mixed halides, like the corresponding alkaline earth mixed halides, have been shown to crystallize in the PbFCl structure type (Table 2). The compound PbFCl forms a layered, tetragonal structure in which the Pb(II) cation is surrounded by five chlorine and four fluorine anions. For the M(II) (M = Ba, Sr, Eu, Ca) mixed halides, which also belong to the PbFCl structure type, the metal coordination sphere may be defined in two ways. The structure of the fluoride-chlorides can be described as a three-dimensional cation coordination lattice, whereas that of the fluoride-iodides may be visualized as a layered structure. These structural differences have been discussed in detail.H Two mixed halide phases of EuClBr have been prepared. These are: EUC10.468r1.56 and EuC10.168r1.85. The methods used to prepare these mixed halides involved (1) heating, in vacuo, a 1:1.25 molar ratio of EuCl3zNH4Br with subsequent removal of the excess ammonium halide, and (2) dehydration of a mixture which consists of the hydrated lanthanide halide and ammonium bromide. The unit cell of crystals grown from the first phase was determined to be orthorhombic with lattice parameters: a_= 7.8797 :_O.00035, O b = 9.197 :_O.OO43, and g_= 4.6111 10.0020 A. The structure was - 7 solved based on the atomic coordinates of EuCl2 (PbCT2 structure -.- my»- .—-. WVH__ .- 5.5—— Iu- “I ' Table CaFCl CaFBr CaFT SrFCI SrFBr SrFI EuFCl EuFBr BaFCl BaFBr BaFI EuFCl 5 Table 2. Lattige Parameters of MFX Compounds With the PbFCl Structure Type. [m In CaFCl .894(3) 3 6.809(6) A CaFBr .883(l) 8.051(3) CaFI .29 8.70 SrFCl .129(2) 6.966(4) SrFBr .218(2) 7.337(5) SrFI .253(2) 8.833(7) EuFCl .118(2) 6.971(3) EuFBr .219(2) 7.312(5) EuFI .249(2) 8.732(4) BaFCl .391(3) 7.226(4) BaFBr .503(2) 7.435(4) BaFI .654(3) 7.977(5) EuFCl .127 6.9844 .075(6) 7. i -Jln-Iu“ - - t—r— —— A type) w‘ for chi; chloride Them phases c properti Gac exhibits more typ were cho type) with various concentrations of bromide ion substituted for chloride ion. The substitution of the bromide ion for a chloride was found to be selective rather than random. The intent of this work was the preparation of mixed halide phases of gadolinium and possibly a study of their structural pr0perties. Gadolinium was chosen, primarily because it usually exhibits only one oxidation state, +3, and thus appears to be a more typical lanthanide than does europium. The halogens, I-Cl, were chosen primarily to simplify analytical problems. CHAPTER II BACKGROUND AND THEORETICAL CONSIDERATIONS we re: mei Attl wher dECOI PREPARATION OF ANHYDROUS LANTHANIDE HALIDES Numerous methods have been reported in the literature for preparing anhydrous lanthanide halides. Of the anhydrous halides, the chlorides have been studied the most. Although lanthanide halides can be made directly from the elements, such schemes were limited by the lack of availability of pure metals. When all metal salts were considered, oxides appeared to be the most likely starting candidates because they were available in the highest purity. In addition, many elements occur naturally in the form of their oxides. ‘2 reviewed several methods for preparing lanthanide Taylor halides. He concluded that many methods which yield pure chlorides use the oxides with volatile reagents that act simultaneously as reducing and chlorinating agents. Among the first compounds used were volatile halides of carbon such as: CC14, HCCl3, COCTZ. Later reactions used SClz, SZCTZ, and SOCl2 as reactants. Many of these methods yield impure products. Hydrated salts of the rare earth metals are readily obtained by reaction of the sesquioxides with hydrohalic acid solutions. Attempts to dehydrate these salts often lead to their hydrolysis: LnX3-H O-anOX + ZHX 2 where X = Cl, Br, or I. The anhydrous triiodide also undergoes decomposition in the presence of oxygen: LnI3 + 1/202 + LnOI + 12 . -meu—- -< .a —.—i Hydrolyi complei' halide. Ta, preparae appropr ammoniul sis of obtainel Re trihalb involve halide. 0f the Nb reactan Carter- 0f gran STRUCTU Hydrolysis can be prevented by performing the dehydration in a completely moisture and oxygen free atmosphere of the hydrogen halide. . Taylor and Carter13 have described a general method for the preparation of lanthanide(III) halides. It consists of heating, in vacuo, a mixture of the hydrated lanthanide halide with the appr0priate ammonium halide to first expel the water and then the ammonium halide. The ammonium halide is thought to prevent hydroly- sis of the lanthanide halide, thus permitting a pure product to be obtained. Recently, a new method for preparing anhydrous lanthanide 14 This method trihalides was described by Carter and Murray. involves the reaction of the rare earth metal with excess mercuric halide. This technique can be utilized at the present time because of the availability of pure metal samples. While all of these methods yield suitable products if pure reactants are used, most are limited to small sample sizes. The Carter-Murray procedure has the added feature of allowing preparation of gram size samples. STRUCTURAL INFORMATION Structural data for the lanthanide(III) chlorides and iodides are illustrated in Table 3. Gadolinium trichloride has a UCl3 structure type. The metal ion is nine-coordinated and is surrounded by chloride ions which define a tricapped trigonal prism. The three chlorides in the 10 Table 3. Structural Types Reported For Lanthanide Halides METAL HALIDE Chloride Ref. Iodide _Ref. La UCl3 16 PuBr3 17 Ce U013 18 PuBr3 l7 Pr UCl3 18 PuBr3 17 Nd UC13 l6 PuBr3 17 Pm UCl3 2 --- l8 Sm UCl3 18 BiI3 l7 Eu UCl3 l6 --- 18 Gd U013 16 BiI3 l7 Tb ' PuBr3 2 BiI3 l7 Dy YCl3 l8 BiI3 17 Ho YCl3 18 BiI3 17 Er . YCl3 18 8113 17 Tm YCl3 18 BiI3 17 Yb YCT3 18 BiI3 17 Lu YCl3 18 BiI3 l7 Iv It‘d-— ' Jan: MIL!” .1 .w A perpenc deternii tricab: Ga type. hedron Asprey, THE_APE Th This re combour TI freque' 0f the 331 Where the f( Gaseot does r bef0r5 Solitt FFEOUe DEIOW ; 11 tricapped positions lie in the same plane as the metal, approximately perpendicular to the faces of the prism. The structural details were 15 16 determined by Au and Au and refined by Morison. Gadolinium triiodide crystallizes in the hexagonal BiI3 structure type. The metal resides at the center of an almost perfect octa- hedron of iodide ions. The structure of GdI3 was determined by 17 Asprey, Keenan and Kruse through powder diffraction techniques. THE APPLICATION OF FAR INFRARED SPECTROSCOPY 1 The region beyond 650 cm' is considered to be the "far infrared." This region is important in the study of organometallic and inorganic compounds with heavy atoms and non—ionic bonds. The vibrations of molecules are not random but occur at specific frequencies determined by the atomic masses and the strengths of the chemical bonds. The vibrational frequencies can be expressed 5:.L/5 2nc u where U'is the frequency of vibration, c is the speed of light, k is as: the force constant, and u is the reduced mass of the atoms involved. The spectrum obtained depends on the physical state of the sample. Gaseous samples usually exhibit rotational fine structure. A solution does not because molecular collisions in the condensed phase occur before a rotation is completed. In addition, frequency shifts, band splitting and additional bands appear in the liquid and solid states. Frequently, the additional bands in the solid state spectrum appear below 300 cm".‘9 fill-mil,“- '-I “ 011sz _l 'Lsc—w‘ r 2,2 _..—~ . i.e., lattic Ir vibrat frequeh of the The V11 other I T are pa The syr| tenned genera rules in the vibrat 12 The bands below 300 cm'1 are often caused by lattice vibrations, i.e., translational and torsional motions of the molecules in the lattice. These vibrations can interact with the intramolecular vibrations to form combination bands and can cause pronounced frequency shifts. An additional complication arises if the unit cell of the crystal contains more than one chemically equivalent molecule. The vibrations of the individual molecules can then couple with each other and give rise to frequency shifts and band splittings. The low-frequency molecular vibrations found in the far-infrared are particularly sensitive to the overall structure of the molecule. The symmetry of the surroundings of a molecule in the unit cell, termed the "site symmetry," determines the selection rules. The general problem of the effect of site symmetry on the selection rules has been treated theoretically.20’21 Bands that are forbidden in the gaseous state often appear in the solid, and degenerate vibrations in the gaseous state are split in the solid. As a result of all these possible complications, the inter- pretation of spectra obtained on solids is difficult. POTENTIOMETRIC DETERMINATION OF CHLORIDE AND IODIDE The wet chemical technique involved potentiometric titrations and has been thoroughly described in the literature.22 SOLID SOLUTIONS Solids are capable of dissolving other materials to form what is termed 51 solid solution.23’24 Thus, a solid solution is simply a solid phase which contains more than one component. The phase rule ‘Jh-‘qunn‘ '3..‘— —-—~ makes or 51 that liqu 5011 the are sol onr 50' Si: wh' so' COT may the con misc line ITQU AdXimr the a 13 makes no distinction as to the state of the phase (gas, liquid or solid) that dissolves; it only deals with the number of phases that are present. Therefore,most of the phase diagrams typical of liquid-vapor and liquid-liquid systems have counterparts among the solid-liquid or solid-solid systems. Solid solutions can form between two or more components provided 'that their atomic radii and valence electronic and crystal structures are similar. Although these conditions constitute good guidelines, they are not necessarily adhered to. Based on structural grounds, two general classes of solid solutions can be distinguished. A substitutional solid solution is one in which solute atoms or groups of atoms are substituted for solvent atoms or groups. This type of substitution is limited by the size of the atoms or groups. An intersitial solid solution is one in which solute atoms or groups of atoms occupy the interstices of the solvents crystal structure. However, the solute atoms must be small compared to the solvent atoms in order to fit in the interstices. Just as two liquids can be partially miscible, so also may two solids. Thus if the components are completely miscible in the solid state, the solid solution constitutes one phase, and a continuous solid solution can be formed. If there is only partial miscibility, a broken series of phases may be formed. The crystal- line solid solutions can be formed either by sublimation or from the liquid-phase. Binary systems which form solid solutions may exhibit either a maximum or minimum in melting point. These liquidus-solidus curves have an appearance similar to that of the liquid-vapor curves in 14 systems which form azeotropes. The mixture having the composition of the maximum or minimum of the curve melts sharply and simulates a pure substance in this respect, as does an azeotrope. CHAPTER III EXPERIMENTAL MATERIALS, EQUIPMENT AND PROCEDURES 15 lawman-tum... unite ‘ 4 43“ CHEMICALS (a) gadolinium oxide, 99.9%, Michigan Chemical Corp., St. Louis, MI; (b) gadolinium metal sponge, 99.9%, Lunex Co., Davenport, IA; (c) potassium nitrate, mercuric chloride, sodium sulfite, cupric sulfate and potassium iodide, reagent grade, Matheson Coleman and Bell, Norwood, OH; (d) sodium chloride, reagent grade, Allied Chemical, New York, NY; (e) mercuric iodide, reagent grade, Mallinkrodt Chemical Works, St. Louis, MO; (f) ammonium chloride, certified ACS, Fisher Scientific Co., Fair Lawn, NJ; (9) argon, Air Reduction Co. Inc., New York, NY; (h) nitrogen, technical prepurified, Air Reduction Co. Inc., New York, NY; (i) silver nitrate, 99.9%, J. T. Baker Chemical Co., Phillipsburg, NJ; (j) mercury, hydrochloric and nitric acid, analytical reagent, Malfinckrodt, St. Louis, MO; (k) agar, laboratory grade, Fisher Scientific Co., Fair Lawn, NJ. Chemicals were used as received without further purification. MATERIALS (a) vitreous carbon boats, Beckwith Carbon Corp., Van Nuys, CA; (b) quartz tubing, Englehard Industries, Inc., Hillsdale, NJ; (c) platinum, J. Bishop and Co., Malvern, PA; (d) fluorolube, Hooker Chemical Corp., Niagara Falls, NY; (e) parafilm "N," American Can Co., Neenah, WI; (f) mineral oil, Fisher Scientific Co., Fair Lawn, NJ. PREPARATIVE PROCEDURES AND EQUIPMENT Anhydrous Lanthanide(III) Chlorides Gadolinium trichloride was prepared according to the methods 13 and Carter and Murray.14 16 of both Taylor and Carter seSOU' 100 m7 oxide, until to dry vigoro 1 shown 225°C was t1 the NI remove ampou box fc Quart; heatir The a; transf high a. and 01 CD 11 HBTghg 17 A. Taylor-Carter Procedure Reagent grade ammonium chloride was mixed with gadolinium sesquioxide in a 6:1 molar ratio. This mixture was then added to 100 ml of 6 N_HCl and the mixture dissolved with heating. This oxide, like those of the other heavier lanthanides, did not dissolve until the mixture was boiled. The solution was then gently evaporated to dryness and towards the end of the evapOration, was stirred vigorously to prevent the white solid from sticking to the beaker. The white powder was then transferred to the drying vessel shown in Fig. l. The vessel was evacuated and the sample heated at 225°C for approximately 8 hours to remove the water. The temperature was then increased to 300°C and maintained for ~11 hours to sublime the NH4C1. The apparatus was permitted to cool, the furnace was removed, and the drying vessel was sealed off under vacuum. The ampoule thus formed was then transferred into the argon-filled glove box for storage and future handling. This crude GdCl3 was subsequently sublimed in an outgassed quartz vessel? as shown in Fig. 2. Sublimation was effected by 5 torr). heating the sample at 950°C for 15 minutes in high vacuum (mlO' The apparatus was allowed to cool and the sublimation vessel was transferred from the quartz heating tube to a transfer tube under a high argon flow. The transfer tube was then capped, evacuated and placed in the glove box. 8. Carter-Murray Procedure An appropriate amount of 99.9% pure gadolinium metal sponge was weighed in air and placed in an outgassed quartz test tube. To this 18 .m _mmmm> 0530.0 mooEEO ace... cmooEz Ezcjm xoooaem E::oo>.< Pouu mo cowumceamen ecu cow umm: mzpmcmaaw mcwzgo .p mezawm mar—Rmdfimd 92.5K— A 2/ 7% _omm 2 : III-.32. in 33135. Mania 2 .IIIIIV E3300) :9: 0* 19 .mmu_~mgwcp msocnxgcm mgu we cowamswpazm Lo; com: mzumcmaam Esaum> saw: .N acumen m3k<¢.o not. $00.52 End: m one. .2630 m j _mmmm> 529533 5530 .o 805:“. .u was... 5.65:. .m \CEm 80.4. J0 Pilillv F532 :9; 2 J was a. Na S e "I in the was p’ exists the se ampoul crude G utiliz mercur dESCri Ch10r4 20 was added a fourfold molar excess of mercuric chloride. The tube was evacuated and sealed; the ampoule so formed was then placed in the furnace overnight, shown in Fig. 3, and heated at 300°C. It was placed in the furnace such that a slight temperature gradient existed between the two ends of the ampoule. This gradient aided in the separation of the mercury products from the crude GdCl3. The ampoule was allowed to cool and transferred to the glove box. The crude GdCl3 was subsequently sublimed in the manner described above. Anhydrous Lanthanide(III) Iodides Gadolinium triiodide was prepared by the Carter-Murray method utilized for preparation of the chloride. A fourfold excess of mercuric iodide was used. Lanthanide(III) Mixed Halide The mixed halide was prepared both by a method similar to that described by Carter and Murray and by direct melting of the tri- chloride and triiodide. A. Pseudo Carter-Murray Procedure A l:O.5:n_molar ratio of 99.9% pure gadolinium metal sponge: mercuric chloride:mercuric iodide was sealed in an outgassed quartz tube under vacuum and heated in a furnace overnight at 300°C. The ampoule was allowed to cool and subsequently transferred into the glove box. In these preparations initially 0.5 §_n_g_6.0; as a result of later investigations fl_was fixed at 4. .2, ..4 3141‘ "a .u “.33 8‘ fig? .. Figure 21 WW . . , I \‘Fnetol IIQUId hollde Ieve '1/ Figure 3. The reaction is carried in a quartz ampoule which is placed in a furnace overnight at 300°C. l Mdfixtw untmx boat then which rate in th mercu absen grey for f carbo assem and a 0” thi POWdeI hand]. 600°C r9510; 22 The sample was pulverized and placed into an outgassed carbon boat in the glove box and then removed in the transfer tube. It was then Slowly heated (~50°C per hour) to 500°C under high vacuum, at which temperature it was maintained for mlO hours. The slow heating rate was necessary to prevent loss of the powdered product and to aid in the separation of the mercury contaminants. When the unwanted mercury products appeared to have been removed, as evidenced by the absence of the red or yellow coloration of Hg2+ compounds, the light grey sample was allowed to cool and transferred to the glove box for further handling. In one preparation the sample was again placed in an outgassed carbon boat which was inserted in an outgassed quartz tube. This assembly was heated (ml50°C per hour) under high vacuum to 550°C and allowed to remain for several hours. A white sublimate appeared on the surface of the quartz tube} The apparatus was cooled and the powder and sublimate again removed to the glove box for further handling and storage. The process was repeated two more times, first heated to 600°C and then 700°C at which temperature both the sublimate and residue appeared white. B. GdCl3 + GdI Melt 3 A 1:1 molar ratio of GdCl3zGdI3 was sealed in a degassed quartz ampoule and heated in a furnace until melted (W700°C). The mixture was allowed to cool Slowly (m50°C per hour) until the melt Ibaszttv. 1 Armada; m ' " 1.6... retry iurnaI the g which glove manif to re remov taine ELEN-E dissc until of 1 two 5 separ DrOCe 23 recrystallized at about 550°C. The ampoule was removed from the furnace, allowed to cool to room temperature and transferred to the glove box for storage. Storage of Samples All of the lanthanide halides were stored in snap cap vials which were sealed in PVC bags in the recirculating argon atmosphere glove box, which has been described previously.25 The purification manifold of the glove box contained Linde Molecular Sieve pellets to remove moisture from the argon and a BASF catalytic oxygen remover, R 3-11. A petri dish of phosphorus pentoxide was main- tained in the glove box to aid in the removal of water. ELEMENTAL ANALYSIS Qualitative Analysis Procedures A. Detection of Iodine Approximately 2 mg of sample was placed in a test tube and dissolved in 5 ml of distilled water. To this was added 6 [_HNO3 until the solution acquired a pH §_l. One ml of CCl4 and one drop of 1 _F__KNO2 were added and the mixture shaken vigorously until the two solutions were mixed well. The two phases were allowed to separate and the violet color in the CCl4 layer was removed. The process was repeated until all iodine had been removed.26 8. Detection of Chlorine After all of the iodine had been removed, the solution was heated over a flame and 1 drop of AgNO3 was added. A white precipitate indicated the presence of chloride.26 A " “-536 swarm ~ Ipfl , , . ,K..‘3&uys,.gus- . ' flaw» m was P' C0099 solut depeh titra Fishe elect indic gassi to us 1.5 g disso Plate mixtui Until bGCWQE 24 C. Test for Mercury One drOp (.05 ml) of potassium iodide-sodium sulfite solution was placed on a piece of filter paper, followed by a drop of c0pper sulfate solution. Finally a drop of approximately 1 N sample solution was added. If mercury were present a red or orange color, depending on the quantity, would be expected.27 Quantitative Analysis Procedures A. POtentiometric Determination of Chloride and Iodide The determination of chloride and iodide was effected with the titration assembly shown in Fig. 4. Measurements were made with a Fisher Accumet pH Meter (model 320). A silver wire and a calomel electrode (Fisher Scientific Co., Pittsburg, PA.) served as the indicator and reference electrodes, respectively. The Ag wire was sensitized by dipping it into 8 f__HNO3 until gassing began. The wire was washed with distilled water prior to use. Between titrations, the calomel electrode was stored in l EKNO3 and washed with distilled water prior to use. The salt bridge28 was prepared by adding 15 g of KNO3 and 1.5 g of agar to 50 ml of distilled water. This mixture was dissolved by heating on a steam bath and then placed on a hot plate until bubbling ceased and the solution began to gel. This mixture was then poured into a U-shaped tube and allowed to cool until gelled. This salt bridge was stored in saturated KNO3 solution between titrations. $351.34.; lu~ raw-wr‘" 1' Figure 4. 25 _Apparatus used for the potentiometric determination of chloride and iodide. 26 5:5 23:09: .I 5228 mEEOm .0 can GEE; ozmcooE m .5839: EM .825 d 82.5 :8 mozxo mozx n. _ .m moohoflm 8:838 .4 .8 mesmwd mean: can mo_mon_IU *0 ZO_._. residue (mixed halide) I Iao-soo cm" J r I Figure 15. Far infrared Spectrum of the residue prepared at 700°C. - ,5 033.51.. 4.. 113. _a 5.38.3 47 atmosphere, conversion to the hydrates occurred. When the humidity lowered, it was possible to store the materials in the glove box for a few weeks without their becoming contaminated. After this period of time, primarily the oxyhalides were produced. (AME—Ens“ Hal .. h... m u. a. “thawing ., v n CHAPTER V DISCUSSION 48 FAR-INFRARED ANALYSIS OF GdCl AND GdI 3 3 Very little use has been made of i.r. techniques for structural analysis of pure solids. This is probably due to the extreme diffi- culty encountered in interpreting the data theoretically. Taylor32 investigated the dependency of infrared spectra on structure for several rare earth halides. He measured the i.r. absorption spectra for the fluorides, chlorides, bromides, and iodides of several rare 1 earth metals over a frequency range of 4000-200 cm' . From these spectra he was unable to distinguish between crystal structure types. Taylor may have been able to obtain more information had he studied the region below 200 cm'], The vibrational and structural properties of a number of rare earth dihalides and trihalides have been studied recently/.33"35 These investigations employed the general technique of high- temperature matrix isolation spectrOSCOPY, which has been described by several investigators.33 Of the five characteristic absorption bands observed in the l infrared spectrum of GdI3, only the band at 383 cm' was also 32 32 reported by Taylor. The GdCl3 spectrum was not reported by Taylor. INITIAL INVESTIGATIONS ‘4 noted that excess mercuric halide was Carter and Murray essential in their preparation of LnX3 because the reaction proceeds smoothly only when the metal is completely immersed in the liquid melt. 49 50 After preparations with a l:n_3 2:0.5 molar ratio of Gd:HgC12: HgI2 had been effected, it was concluded that formation of GdCl3 was more favorable than either formation of GdI3 or a mixed halide phase. Any GdI3 or Gd(Cl, I)3 formed probably reacted with the less volatile HgCl2 and iodide ion was displaced as HgIZ, which sub- sequently decomposed to Hg and 12. In subsequent preparations, a variable excess of HgI2 was used in the molar ratio, GdzHgClzzHgI2 = 1:0.5zn, The far-infrared spectrum taken immediately after sample preparation for the n_= 5.6 sample, gave evidence for the formation of GdI3 and a mixed halide phase. The five characteristichI3 absorption bands are present along wtih one strong absorption at approximately 223 cm']. This latter band was attributed to the presence of a mixed Gd(Cl, I)3 phase. Exposure of the reaction products to the glove box atmosphere yielded hydrates, apparently the glove box was not sufficiently devoid of water. During the investigation of preparations in which n_= 3.5, the reaction product was converted to pure GdOCl, Appendix N, apparently from contamination of only trace amounts of water present in the glove box atmosphere. Due to the relatively small sample size involved in the powder diffraction analysis, the possibility of hydration to occur while the camera is being evacuated cannot be excluded. THE MOLAR RATIO HgIZ:Gd = 4.0 The only difference in the experimental conditions for the preparations of heatings 1 through 4 was the temperature. X-Ray powder diffraction patterns obtained for the residue and sublimate 5E§.i§afifi 51 of every phase were analyzed and compared. It was found that certain distinct.sharp lines that were correlated with the formation or absence of new bands in the i.r. appeared or disappeared in the X-ray powder photographs. From comparison of the infrared spectra and the X-ray powder diffraction patterns, it can be seen that the composition of the sample varies at different temperatures. The composition of the residues are also different from those of the sublimate at each temperature where samples were analyzed. At 450°C the infrared 1, which indicate the spectrum shows two bands, at 120 and 158 cm' presence of GdI3. Two more bands are expected, but instrumental alterations prevented measurements below 100 cm'1. The other bands at 210, 265, 363, 403, and 468 cm"1 indicate the presence of one or more mixed halide phases. The X-ray powder diffraction pattern taken of the sample prepared at 450°C indicates the presence of GdI3, a trace amount of GdCl3 and a mixed halide phase. The infrared spectrum and X-ray powder photograph of the residue remaining at 550°C indicate the absence of GdI3 and a change in the composition of the residue. The only band found in the spectra of the 450 and 550°C products is the absorption band at 210 cm’]. The X-ray powder photograph of the 550°C sample has only a few lines in common with the one taken at 450°C. The infrared spectrum of the residue remaining at 600°C has only four bands in common with that of the 550°C residue: 270, 370, 440 and 475 cm“. New absorption 1 1 bands at 125 cm' (split into two peaks), 215, 316, 408 and 460 cm‘ indicate the presence of a new mixed halide phase at 600°C. The 52 X-ray photograph of the 600°C residue has some lines in common with that of the 550°C residue and, in addition, several new lines appear. The infrared spectrum of the residue remaining at 700°C has some absorption bands that were present in the 600°C residue: 1 1 268, 316, 370, 408 and 475 cm' . The band at 125 cm' is no longer split. The changes in the i.r. absorption bands with specimen preparation temperatures seem to indicate that the composition of the residue varies with respect to temperature. The compositions of the residues and sublimates at a particular temperature also vary. The far-infrared spectra of the sublimate and residue produced at 600°C both have peaks at 125, 215, 240, 268, 1 316, 370, 408 and 475 cm' . In addition weak bands appear at: 107, 143, 155, 180, 207 and 435 cm‘1 in the spectrum of the sublimate. Likewise,the spectrum of the 700°C sublimate has some bands in common with the 700°C residue in addition to other bands. The relative band intensities for certain absorptions also changes in the i.r. spectral series. These intensity changes are taken as evidence for the formation of a number of mixed halide phases, with particular phases apparently stable over select temperature ranges. The mixed halide UClI2 was synthesized but no structural work 3 was done on it.3 The ionic radius of U+ is 1.04 A as reported by Shannon and that of Gd+3 is 0.98 A.34 Since the ionic radii of +3 3 U and Gd+ are relatively close, the two mixed halides may have comparable structure types. 53 The results of the quantitative analysis are of considerable interest. The empirical formulas for the residues and sublimates are summarized in Table 8. Table 8. Summary of Empirical Formulas Temperature °C Residue Sublimate 450 GdC]l.OIZ.O 55° Gdc110411.96 60° GdCl1.08II.92 Gdc11.081I.92 700 GdClLOQI].92 The components of the 450°C preparation,according to the X-ray results are GdI3, a mixed halide phase and a trace amount of GdCl3. The principal components, GdI3 and the mixed halide phase, mask the presence of GdCl3. Thus, its bands are not observed in the i.r., and only after excessive exposure is GdCl3 observed in the X-ray photo- graph. When the excess of mercuric iodide that was used in the preparation is considered, it is not surprising that a fair amount of GdI3 was produced. At 550°C neither GdCl3 nor GdI3 can be seen in the X-ray diffraction or far-infrared results. From comparison of the empirical formulas, it is apparent that as the temperature increases the Cl'/I" ratio increases in the residue. The similarity between the empirical formulas of the sublimates at 600°C and 700°C, is indicative that the sublimate has a constant composition regardless of the temperature of formation. tswflnwflfia. .I... gawuflnfia 54 This observed constant composition of the sublimate appears at first glance to be inconsistent with the far i.r. and X-ray powder diffraction results. A careful inspection of the character of the lines on the X-ray films indicates that the product prepared at the higher temperature is considerably more ordered than that prepared at the lower temperature. The extra weak reflections which appear in the pattern of the higher temperature product probably stems from increased order in the solid. Likewise,this increased order produces increased resolution in the i.r. and leads to narrowing of the band widths and peak sharpness. The components of the product formed at 450°C are GdI3, Gd(Cl, I)3, and GdCl3. As the temperature is increased to 550°C these constituents react and produce a sublimate. The composition of the residue at 550°C consists of a new series of mixed Gd(Cl, I)3 phases. Since the vapor pressure of GdI3 is greater than that of GdCl3, the vapor is assumed to be GdCl3 and GdI3 which again react an the hot surface of the sublimation tube to form a series of mixed halide phases different from those in the residue. That the composi- tion of the vapor is apparently rich in iodide can be seen in the increasing molar ratio of Cl-/I' as the temperature increases, in the empirical formulas of the residues. The observation is consistent with the valatilities of the trichloride and triiodide. As the temperature is raised to 700°C the composition of the residue becomes more chloride rich and a vapor phase of GdCl3 and GdI3 which again react to form a series of mixed halide phases is observed. Due to 55 the initial small sample size, at 700°C a very small amount of residue remained. The composition of the vapor might be determined by quenching. THE MOLAR RATIO HgIzzGd = 3.5 The X-ray powder diffraction data along with the infrared spectra indicate that at 500°C no GdI3 or GdCl3 was present. The absence of the pure halides is consistent with the increased preparatory temperature. It appears that a number of mixed halide phases is present, probably as a result of a lack of equilibrium in the system. When the temperature was raised to 550°C the only product found was GdOCl. The formation of GdOCl with liberation of 12 was a result of water contamination which attacks the sample in the glove box atmosphere. SOLID SOLUTION At the present time it is difficult to conclude positively whether these mixed halide phases are a continuous series of solid solutions or a series of discrete phases. However, the formation of a solid solution is unlikely. The difference in structure type of GdI3 and GdCl3 would probably prevent formation of a continuous solid solution. The large difference in ionic radii36 between the chloride, 1.8. A, and iodide, 2.16 A, also makes the formation of a solid solution unlikely. However, particular sets of distinct sharp lines were observed, not a continuous shifting. A solid solution was postulated for the uranium mixed halides. However, the structure types of the uranium halides are different from those of gadolinium. CHAPTER VI CONCLUSIONS AND SUGGESTIONS FOR FURTHER RESEARCH 56 CONCLUSIONS AND SUGGESTIONS FOR FURTHER RESEARCH One may conclude from this work that an undetermined number of mixed halide phases has been prepared. It is impossible to definitely conclude whether a series of compounds or a solid solution has been formed. Evidence seems to indicate that the formation of a solid solution is unlikely. The use of far-infrared spectroscopy has proven to be an important tool in determining the presence of the mixed halide phase. This investigation, as with many, appears to have raised more questions than it has answered. Further investigations with different preparatory methods may lead to isolation of the different mixed halide phases. Investigation of GdCl3 + GdI3 melt preparation, by varying the stoichiometry of the reactions and examining closely the X-ray and far-infrared data,may answer the question of whether a solid solution has been formed. The composition of the vapor might be determined by quenching. 57 as“... semifinafia - m? I. APPENDICES Abmfih‘é. I. ”WM”! N» 1:. _fianhwgflrwufla . {a w APPENDIX A Observed sinzeix = 1.54051 )1) and Interplanar d-Values for GdCl3 Relative d-Value Intensity A sinze 5 6.617 0.0136 10 4.194 0.0337 3 3.754 0.0422 6 3.508 0.0482 2 2.780 0.0768 6 2.547 0.0945 1 2.142 0.1293 4 2.097 0.1349 1 2.070 0.1384 1 1.807 0.1817 1 1.736 0.1970 1 1.633 0.2226 1 1.569 0.2407 1 1.485 0.2691 1 1.343 0.3287 1 1.262 0.3726 1 1.193 0.4166 58 .831 .53....4333 . __W . . e .1. APPENDIX 8 Calculated sin2 0 (A = 1.54051 A) and Interplanar d-Values for GdCl 3 Relative d-V lue 2 Intensity 3 sin e 9 6.3794 0.0146 7 3.6832 0.0437 10 3.4526 0.0498 2 3.1897 0.0583 1 2.7417 0.0789 6 2.5189 0.9350 2 2.4112 0.1020 3 2.1265 0.1312 7 2.0792 0.1372 1 2.0530 0.1408 1 1.9543 0.1553 2 1.8416 0.1749 2 1.7932 0.1845 1 1.7693 0.1895 1 1.7263 0.1991 3 1.6249 0.2247 1 1.5949 0.2333 1 1.5631 0.2428 1 1.4660 0.2684 2 1.4770 0.2720 1 1.4635 0.2770 2 1.3921 0.3063 2 1.3786 0.3122 1 1.3708 0.3157 1 1.3403 0.3303 1 1.3382 0.3313 1 1.2759 0.3645 1 1.2595 0.3740 1 0.2577 0.3750 1 0.2277 0.3936 1 1.2184 0.3996 1 1.2056 0.4084 1 1.1917 0.4178 1 1.1903 0.4188 1 1.1568 0.4434 2 1.1522 0.4469 1 1.1458 0.4519 1 1.1036 0.4871 1 1.0837 0.5052 59 60 APPENDIX B. (Cont'd.) Relative d-Vglue 2 Intensity sin 0 1 1.0826 0.5062 1 1.0632 0.5248 1 ' 1.0573 » 0.5344 1 1.0488 0.5394 483.443.45.43wa _ APPENDIX C Observed sin20 (A = 1.54051 A) and Interplanar d-Values for GdI3 Relative I d-V lue Intensity . R sinze 2 6.4132 0.0144 5 4.2088 0.0335 2 3.8579 0.0399 10 3.3842 0.0581 3 2.6052 0.0874 1 2.5041 0.0946 2 2.3071 0.1115 10 2.2214 0.1202 1 2.1171 0.1324 1 2.0084 0.1477 1 1.8756 0.1687 7 1.8547 0.1725 2 1.6885 0.2081 1 1.4910 0.2669 4 1.4244 0.2924 2 1.3442 0.3284 1 1.2823 0.3608 1 1.2050 0.4086 61 53.3.51. 3... .. 4.431....” wflflwg I. . L. APPENDIX 0 Calculated sinze (x = 1.54051 A) and Interplanar d-Values for GdI3 Relative d-V lues - 2 Intensity 1 sin 0 2 6.4935 0.0141 1 6.1952 0.0155 1 3.7490 0.0422 10 3.6889 0.0436 8 3.5245 0.0478 1 3.2467 0.0563 2 3.2074 0.0577 5 2.4543 0.0985 5 2.4372 0.0999 1 2.3880 0.1040 3 2.1645 0.1266 1 2.1527 0.1280 1 2.1186 0.1322 2 2.0651 0.1391 1 1.8745 0.1688 1 1.8668 0.1702 2 1.8444 0.1744 1 1.8088 0.1813 1 1.8010 0.1829 1 1.7942 0.1843 2 1.7743 0.1885 1 1.7622 0.1910 1 1.7425 0.1954 2 ‘ 1.6184 0.2265 1 1.6037 0.2307 1 1.5801 0.2376 1 1.4897 0.2673 1 1.4859 0.2687 1 1.4745 0.2729 1, 1.4561 0.2798 1 1.4315 0.2895 2 1.4137 0.2969 1 1.4039 0.3010 1 1.3880 0.3080 1 1.3666 0.3177 1 1.3405 0.3302 1 1.2961 0.3532 1 1.2762 0.3642 62 .2 .mflnflaa ”a .33.... “.3333 63 APPENDIX D. (Cont'd.) Relative d-Vglues 2 Intensity sin 0 1 1.2596 0.3740 1 1.2497 0.3799 1 1.2296 0.3924 1 1.2271 0.3940 1 1.2250 0.3954 1 1.2186 0.3995 1 1.2082 0.4065 1 1.1940 0.4162 1 1.1765 0.4287 1 1.1748 0.4298 1 1.1663 0.4362 1 1.1644 0.4376 1 1.1589 0.4417 1 1.1499 0.4487 1 1.1225 0.4709 APPENDIX E 0 Observed sinze (A = 1.54051 A) and Interplanar d-Values for the Product Produced at 500°C for the Molar Ratio Hglzzed = 3.5 Relative d-Values Intensity A sinze 2 6.9725 0.0122 2 3.4807 0.0490 10 3.3156 0.0540 1 3.01775 0.0652 1 2.7426 0.0789 5 2.5559 0.0908 5 2.1662 0.1264 1 1.9757 0.1520 64 APPENDIX F Observed sinze (A = 1.54051 A) and Interplanar d-Values for the Product Prepared at 450°C Relative d-Vglues 2 Intensity sin 0 3‘ 7.0210 0.0120 2 6.4165 0.0144 1 6.1082 0.0159 1 5.5932 0.0190 1 5.2877 0.0212 2 5.1632 0.0223 1 4.9664 0.0241 2 4.7970 0.0258 1 4.5366 0.0288 4 4.2770 0.0324 1 4.1872 0.0338 8 4.1228 0.0349 1 4.0446 0.0363 6 3.8707 0.0396 5 3.7389 0.0424 2 3.4913 0.0487 2 3.3743 0.0521 10 3.3353 0.0533 1 3.2034 0.0578 1 3.1621 0.0593 4 3.0871 0.0623 3 2.9778 0.0669 1 2.8431 0.0734 2 2.8187 0.0747 2 2.7548 0.0782 1 2.7199 0.0802 1 2.6632 0.0837 1 2.5829 0.0889 8 2.5660 0.0901 3 2.5235 0.0932 1 2.4973 0.0951 1 2.4466 0.0991 2 2.4016 0.1029 2 2.3464 0.1078 1 2.3128 0.1109 1 2.2143 0.1210 6 2.1907 0.1236 65 66 APPENDIX F. (Cont'd.) Relative d-Values 2 Intensity sin e 2 2.1342 0.1303 2 2.1091 0.1334 1 2.0849 0.1365 4 1.9805 0.1513 1 1.8518 0.1730 '2 1.8286 0.1774 1 1.8128 0.1805 2 1.6683 0.2123 1 1.6518 0.2175 1 1.5951 0.2332 1 1.4679 0.2754 1 1.4019 0.3019 1 1.3631 0.3193 uTy 5......finaax...“ a... .33. Ms K“. 51wa .U . . LI- ...b APPENDIX G Observed sinZB (x = 1.54051 A) and Interplanar d-Values for the Residue Produced at 550°C i? v _‘| MI! - .. n.- 3*! Relative d-Vilues . 2 nten51ty Sln e 2 6.9201 0.0124 1 4.2578 0.0327 3 3.8407 0.0402 3 3.7648 0.0419 3 3.4050 0.0512 10 3.2754 0.0553 10 3.0043 0.0557 3 2.8044 0.0754 1 2.7515 0.0784 2 2.5408 0.0919 2 2.0113 0.1467 1 1.9832 0.1508 1 1.9025 0.1639 1 1.9729 0.1524 1 1.7418 0.1955 1 1.6502 0.2179 67 APPENDIX H Observed sin20 (X = 1.54051 A) and Interplanar d-Values for the Sublimate Produced at 550°C Relative d-Vglues 2 Intensity A sin 0 3 6.8842 0.0125 1 6.7529 ' 0.0130 1 3.6529 0.0445 1 3.4911 0.0487 1 3.4351 0.0503 1 3.2632 0.0557 3 3.0061 0.0657 10 2.1389 0.1297 68 APPENDIX I Observed sin20 (X = 1.54051 A“) and Interplanar d-Values far the Residue Produced at 600°C Relative ~d-V lues Intensity g sinze 3 6.7937 0.0129 1 6.2909 0.0150 5 3.6309 0.0450 5 3.4583 0.0496 5 3.2797 0.0552 10 2.9989 0.0660 2 2.7921 0.0761 1 2.7266 0.0798 1 2.5370 0.0922" 2 2.1388 0.1297 1 2.1026 0.1342 1 1.9778 0.1517 69 IL $35 .3. 32.31.... gag APPENDIX J Observed sin2 6 (A= and Interp1anar d-Va1ues for the Sub11mate Produced at 600°C Re1atiye d-Va1ues . 2 Intens1ty s1n e 5 6.8967 0.0125 1 6.4950 0.0141 1 4.2875 0.0323 1 3.8488 0.0401 2 3.6668 0.0441 2 3.4949 0.0486 10 3.2814 0.0551 7 3.0112 0.0654 5 2.5271 0.0929 10 2.1443 0.1290 1 2.1074 0.1336 2 2.0424 0.1422 1 1.7895 0.1853 70 i a. F, .1" ? ._.._.v..1 -. APPENDIX K Observed sin2 e'(x = 1.54051 3) and Interp1anar d-Va1ues for the Residue Produced at 700°C Relative d-V 1ues Intensity R "' sinze 2 9.5021 0.0066 2 6.9808 0.0122 3 3.6617 0.0443 2 3.5003 0.0484 2 3.2942 0.0547 10 3.0116 0.0654 8 2.8025 0.0755 2 2.4240 0.1010 1 2.3957 0.1034 3 2.1414 0.1293 1 2.1116 0.1331 1 2.0389 0.1427 4 1.9778 0.1517 1 1.7754 0.1882 1 1.8288 0.1774 5 1.64858 0.2183 1 1.5322 0.2527 71 52.2413a1335 ._ 3. 5 ,- -u APPENDIX L Observed sin2 e (X =1.54051 X) and Interp1anar d-Va1ues for the Sub1imate Produced at 700°C Re1ative d-V 1ues Intensity A sinze 3 6.8844 0.0125 2 6.4338 0.0143 2 4.5028 0.0293 2 4.2415 0.0330 2 3.8260 0.0405 3 3.6536 0.0445 3 3.4858 0.0488 2 3.4308 0.0504 2 3.2618 0.0558 8 3.0047 0.0657 5 2.7979 0.0758 10 2.1422 0.1293 2 1.8737 0.1690 72 =r- . “‘1‘"! u APPENDIX M I Observed sinze (X = 1.54051 A) and Interp1anar d-Va1ues for the Product Produced From the GdI3 + GdC13 Me1t Re1ative d-Vg1ues . 2 Intens1ty $1n 8 1 1.1042 0.4866 1 1.1137! 0.4784 1 1.1232 0.4703 1 1.1435 0.4537 10 1.1499 0.4487 2 1.1708 0.4328 1 1.1772 0.4281 1 1.1838 0.4233 2 1.2235 0.3963 4 1.2556 0.3763 2 1.2663 0.3700 1 1.2741 0.3655 4 1.3053 0.3482 1 1.3455 0.3277 3 1.3659 0.3180 1 1.4517 0.2815 1 1.4527 0.2811 1 1.5169 0.2578 1 1.6316 0.2229 73 figgnudnufii 13.3% n APPENDIX N Observed sinze (A = 1.54051 A) and Interp1anar d-Va1ues for GdOC1 Pe1ative d-Vg1ues . 2 ntens1ty s1n e 1 7.8389 0.0097 1 6.7181 0.0132 1 3.5812 0.0463 8 3.3986 0.0514 8 2.7906 0.0762 1 2.7433 0.0788 1 2.6427 0.0850 9 2.4986 0.0950 1 2.1370 0.1300 2 1.9683 0.1531 1 1.7337 0.1974 ,2 1.7025 0.2047 2 1.5567 0.2443 74 APPENDIX 0 Observed sin2 61A =1.54051 K) and Interp1anar d-Va1ues for GdC1 ¥e1ative d-Vg1ues . 2 ntenSIty s1n e 2 6.6044 0.0136 3 6.3809. 0.0146 3 5.4394 0.0201 3 5.0727 0.0231 3 4.8447 0.0253 3 4.5639 0.0284 3 4.4145 0.0304 1 4.1382 0.0347 5 3.9773 0.0375 5 3.5660 0.0467 4 3.4224 0.0507 2 3.1003 0.0673 1 2.5921 0.0883 1 2.5269 0.0929 1 2.4646 0.0977 3 2.4147 0.1018 1 2.3365 0.1087 1 1.1309 0.4638 75 saunas... axinmmmfig ._.. ...1u2 APPENDIX P 2 Observed sin 61). = 1.54051 71) and Interp1anar d-Va1ues for GdI3°flH20 Re1ative d-Va1ues Intensity sinze 1 6.8263 0.0127 1 6.1709 0.0159 1 7.4033 0.0108 1 5.8010 0.0176 1 5.5624 0.0192 1 5.1550 0.0223 10 4.2004 0.0336 9 4.0469 0.0362 6 4.9343 0.0244 6 4.5693 0.0284 9 3.9630 0.0378 2 3.3419 0.0531 7 3.0948 0.0619 7 2.9955 0.0661 7 2.8827 0.0714 8 2.6614 0.0838 4 2.4189 0.1014 9 2.1380 0.1298 6 2.1251 0.1314 3 2.1008 0.1344 8 2.2060 0.1219 3 2.1926 0.1234 2 2.0639 0.1393 1 2.1151 0.1326 1 2.0230 0.1450 2 1.9885 0.1500 4 1.8168 0.1798 3 1.7185 0.1869 2 1.7189 0.2009 2 1.7049 0.2041 1 1.6659 0.2138 1 1.6268 0.2242 1 1.6042 0.2305 1 1.5841 0.2364 1 1.5627 0.2430 1 1.5291 0.2538 1 1.5197 0.2570 76 5.3.3213 afienmmmmwgfi , ._ g. in 77 APPENDIX P. (Cont'd.) Re1ative d-Va1ues 2 Intensity sin 0 1 1.5055 0.2618 1 1.4844 0.2693 1 1.4603 0.2782 1 1.4269 0.2914 1 1.4039 0.3010 . .A x 4 ‘I . eggs s . 2.... .. -3. .. REFERENCES 8.5%...“5.” e... :53. .1 .fidfifiwflflw‘ d O 11. 12. 13. REFERENCES C. Pou1enc, Ann. Chem. Phys., Z8, 2, 28 (1894). D. Brown, "Ha1ides of the Lanthanides and Actinides,” John Ni1ey and Sons Ltd., New York (1968). J. J. Katz and E. Rabinowitch, "The Chemistry of Uranium," Nat. Nuc1. Energy Ser. Div. VIII, V01. 5, McGraw-Hi11, New York, (1951). V. G. Lambrecht, Jr., M. Robbins, and R. C. Sherwood, J. So1id State Chem.,,Lg, 1 (1974). B. Tanguy, M. Pezat, C. Fontenit, C. Fouassier, C. R. Acad. Sc. Paris, Series C, 25 (1973). OKOWNON L. H. Brixner and J. D. Bier1ein, Mat. Res. Bu11., 9, 99 (1974). J. M. Haschke, J. SoIid State Chem.,lLe, 238 (1975). L. H. Brixner, Mat. Res. Bu11., 11, 269 (1976). H. P. Beck, J. So1id State Chem., in press. B. C1ink, M. S. Thesis, Michigan State University, East Lansing, Michigan, 1974. A H. Bgrnighausen, G. Brauer, N. Schu1tz, Z. anorg. a11g. Chem., 3138, 250 (1965). M. D. Tay10r, Chem. Rev., 62, 503 (1962). M. D. Tay1or and C. P. Carter, J. InorgLNuc1. Chem., 24, 387 (1962). 78 {mg-Wan” 1. “a! ”1311.1 “M. flflflwg‘ 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 79 F. L. Carter, J. F. Murray, Mat. Res. Bu11., z, 519 (1972). C. Au, R. Au, Acta Crysta11ogr., 28, 1112 (1967). B. Morosin, J. Chem. Phys., 49, 3007 (1968). L. B. Asprey, T. K. Keenan, F. H. Kruse, Inorg. Chem., 3, 1137 (1964). R. w. G. Nyckoff, ACrysta1 Structures," V01. 2, 2nd ed, '33? Interscience Pub1ishers, New York (1963). S. Krimm, "Infrared Spectra of So1ids," in "Infrared Spectro- scopy and MoIecu1ar Structure," Chapter 8, ed. M. Davies, E1sevier, 1963. é' o. F. Hornig, J. Chem. Phys., q11g, 1063 (1948). H. Winston, R. S. Hayford, J. Chem. Phys., 17, 607 (1949). H. A. Laitinen, N. E. Harris, "Chemica1 Ana1ysis," 2nd ed, McGraw—Hi11, Inc., New York (1975). L. V. Azaroff, "Introduction to So1ids," McGraw-Hi11, Inc., New York (1975). A. Find1ay, "The Phase Ru1e," 9th ed, Dover Pub1ications, Inc., New York (1951). A. V. Hariharan, Ph.D. Thesis, Michigan State University, East Lansing, Michigan, 1971. E. H. Swift, w. P. Schaefer, "Qua1itative E1ementa1 Ana1ysis," N. H. Freeman and Co., San Francisco (1962). F. Feig1, V. Anger, "Spot Tests in Inorganic Ana1ysis," E1sevier Pub1ishing Co., Amsterdam (1972). R. B. Fischer, 0. G. Peters, "Quantitative Chemica1 Ana1ysis," N. B. Saunders Co., Phi1ade1phia, Pennsy1vania (1968). .4 u§$fimfl .. .1. .1... «1.443 waflfiwg‘ I . . . 1. I . . . .ll'll 1" I... III. 29. 30. 31. 32. 33. 34. 35. 36. 80 J. M. Haschke, Ph.D. Thesis, Michigan State University, East Lansing, Michigan, 1969. J. J. Stezowski, Ph.D. Thesis, Michigan State University, East Lansing, Michigan, 1968. 0. Lindqvist, F. Henge1in, Ark. Kemi., 28, 179 (1967). M. D. Tay1or, T. T. Cheung, M. A. Hussein, J. Inorg. Nuc1. Chem., ,34, 3073 (1972). R. D. Hes1ey, C. N. DeKock, J. Chem. Phys., 55, 3866 (1971). C. w. DeKock, R. D. Nes1ey, High Temp. Sci., 4, 41 (1972). J. w. Hastie, R. H. Hauge, J. L. Margrave, High Temp. Sci., 3, 56 (1971). R. 0. Shannon, Acta Crysta11ogr., 58%, 751 (1976). \FLA _ .llllill.’ IN’. IN fgufiasiniiu£3n§ I :L 0 I . . . .. esfifigmi .33... 34.515... L 1-: - 11 u. _ 1 . inifibxu Sufi. .111 a... . . 1 5 m. m... 2.. V v.0 'U. n— 04.... OW‘U" . ”11314311201 STATE I II. 111. 3- 3 129 3