CRYSTAL-STRUCTURES OF BISMUTH TELLUROHALIDES BITEX (X=CL, BR, I) FROM X-RAY-POWDER DIFFRACTION DATA
CRYSTAL-STRUCTURES OF BISMUTH TELLUROHALIDES BITEX (X=CL, BR, I) FROM X-RAY-POWDER DIFFRACTION DATA
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DOI：
10.1006/jssc.1995.1058
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发表时间：
1995-02-01
影响因子：
3.3
通讯作者：
POPOVKIN, BA
中科院分区：
文献类型：
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作者：
SHEVELKOV, AV;DIKAREV, EV;POPOVKIN, BA
碲化铋BiTeCl（首次制备）、BiTeBr和BiTeI的晶体结构基于X射线粉末衍射数据使用全轮廓Rietveld方法进行了精细化。所有三个相都在六方晶系中结晶：BiTeCl;空间群P6（3）mc（No.186），a = 4.2426（1）Angstrom，c = 12.397（1）Angstrom，z = 2，R（I）= 0.065，R（Pr）= 0.104; BiTeBr，空间群P（3），棒m1上（No.164），a = 4.2662（1）Angstrom，c = 6.487（1）Angstrom，z = 1，R（I）= 0.042，R（Pr）0.082; BiTeI，空间群P3 m1（No.156），a = 4.3392（1）埃，c = 6.854（1）埃，z = 1，R（I）= 0.054，R（Pr）= 0.129。碲化铋不属于SbSBr结构类型。BiTeBr具有2 H-CdI 2型结构，碲和溴原子统计地分布在两层堆积中。BiTeI表现出一个扭曲的变形前结构的碲和碘原子在阴离子亚电池的顺序。在BiTeCl中，碲和氯原子层沿晶胞的c方向沿着交替，形成四层（hc）（2）堆积。铋原子占据了第二层中所有的八面体间隙。这三种结构共有的共同特征是波纹状（BiTe）（+）层，其类似于金属铋中铋层的几何形状。该结构描述的半离子模型，根据该模型，铋和碲原子形成带正电荷的（BiTe）（+）层，而铋-卤素接触被认为是离子。(C)出版社：Academic Press
Crystal structures of the bismuth tellurohalides BiTeCl (prepared for the first time), BiTeBr, and BiTeI were refined based on X-ray powder diffraction data using a full-profile Rietveld method. All three phases crystallize in a hexagonal system: BiTeCl; space group P6(3)mc (No. 186), a = 4.2426(1) Angstrom, c = 12.397(1) Angstrom, z = 2, R(I) = 0.065, R(Pr) = 0.104; BiTeBr, space group P (3) over bar m1 (No. 164), a = 4.2662(1) Angstrom, c = 6.487(1) Angstrom, z = 1, R(I) = 0.042, R(Pr) 0.082; BiTeI, space group P3m1 (No. 156), a = 4.3392(1) Angstrom, c = 6.854(1) Angstrom, z = 1, R(I) = 0.054, R(Pr) = 0.129. Bismuth tellurohalides do not belong to the SbSBr structure type. BiTeBr has a 2H-CdI2-type structure with tellurium and bromine atoms statistically distributed within a two-layered packing. BiTeI exhibits a distorted variant of the former structure with an ordering of tellurium and iodine atoms in an anionic subcell. In BiTeCl, layers of tellurium and chlorine atoms alternate along the c direction of the unit cell, forming a four-layered (hc)(2) packing. Bismuth atoms occupy all octahedral interstices in each second layer. The common feature that the three structures share is the corrugated (BiTe)(+) layers which resemble the geometry of bismuth layers in metallic bismuth. The structures are described in terms of a semi-ionic model, according to which bismuth and tellurium atoms form positively charged (BiTe)(+) layers, while bismuth-halogen contacts are considered to be ionic. (C) 1995 Academic Press, Inc.