X-RAY-POWDER DIFFRACTION AS A TOOL FOR FACING TWINS - THE CASE OF THE MONOCLINIC NBCOTE2 AND TACOTE2 PHASES

被引：20

作者：

LI, J ^{[1
]}

MCCULLEY, F ^{[1
]}

MCDONNELL, SL ^{[1
]}

MASCIOCCHI, N ^{[1
]}

PROSERPIO, DM ^{[1
]}

SIRONI, A ^{[1
]}

机构：

[1] UNIV MILAN,IST CHIM STRUTTURIST INORGAN,I-20133 MILAN,ITALY

来源：

INORGANIC CHEMISTRY | 1993年 / 32卷 / 22期

关键词：

D O I：

10.1021/ic00074a029

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

TaCoTe2 has been synthesized from the elements at 900-degrees-C in evacuated silica tubes; the crystals of TaCoTe2 are monoclinic, space group P2(1)/c (No. 14), with a = 8.1524(6) angstrom, b = 6.2649(4) angstrom, c = 7.7945(5) angstrom, beta = 116.789(4)-degrees, and Z=4, and appear to be heavily twinned about the (100) plane. Therefore, powder diffraction data and Rietveld refinement were used to assess the correct stereochemistry of the atoms of this new compound. In addition, the already reported NbCoTe2 compound has been found to be, in the bulk, monoclinic [a = 8.1612(4) angstrom, b = 6.2976(3) angstrom, c = 7.8518(4) angstrom, beta = 117.487(3)-degrees], rather than orthorhombic, and isostructural to TaCoTe2. The stereochemical interpretation of this change of crystal symmetry is given in terms of a significant asymmetrical bending of one tellurium atom toward one Nb (or Ta) atom, making these metals five-, rather than six-, coordinated.

引用

页码：4829 / 4833

页数：5

共 43 条

[31]

MONCONDUIT L, 1992, Z ANORG ALLG CHEM, V616, P1

[32] SYNTHESIS AND STRUCTURE OF NB0.89FE0.93TE2 AND TA0.77FE0.90TE2 [J].

NEUHAUSEN, J ;

STORK, KL ;

POTTHOFF, E ;

TREMEL, W .

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, 1992, 47 (09) :1203-1212

[33] FN - CRITERION FOR RATING POWDER DIFFRACTION PATTERNS AND EVALUATING THE RELIABILITY OF POWDER-PATTERN INDEXING [J].

SMITH, GS ;

SNYDER, RL .

JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1979, 12 (FEB) :60-65

[34] TANI2TE2, A NOVEL LAYERED TELLURIDE, AND TACO2TE2, A STRUCTURAL VARIANT WITH PEIERLS DISTORTION [J].

TREMEL, W .

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1992, 31 (02) :217-220

[35] ISOLATED AND CONDENSED TA2NI2 CLUSTERS IN THE LAYERED TELLURIDES TA2NI2TE4 AND TA2NI3TE5 [J].

TREMEL, W .

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1991, 30 (07) :840-843

[36] ISOLATED AND CONDENSED M2CO2 CLUSTERS (M = NB, TA) IN THE LAYERED TELLURIDES NB2CO2TE4 AND TACO2TE2 [J].

TREMEL, W .

JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1991, (19) :1405-1407

[37]

TREMEL W, 1991, THESIS U MUNSTER

[38]

Van Den Berg J.M., 1968, INORG CHIM ACTA, V2, P143, DOI [10.1016/s0020-1693(00)87012-7, DOI 10.1016/S0020-1693(00)87012-7]

[39] MAGNETIC AND CRYSTALLOGRAPHIC STRUCTURES OF MEXNBS2 AND MEXTAS2 [J].

VANLAAR, B ;

RIETVELD, HM ;

IJDO, DJW .

JOURNAL OF SOLID STATE CHEMISTRY, 1971, 3 (02) :154-&

[40] TREOR, A SEMI-EXHAUSTIVE TRIAL-AND-ERROR POWDER INDEXING PROGRAM FOR ALL SYMMETRIES [J].

WERNER, PE ;

ERIKSSON, L ;

WESTDAHL, M .

JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1985, 18 (OCT) :367-370

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