PREPARATION, STRUCTURE, AND PROPERTIES OF SOME CHROMIUM SELENIDES - CRYSTAL GROWTH WITH SELENIUM VAPOR AS A NOVEL TRANSPORT AGENT
PREPARATION, STRUCTURE, AND PROPERTIES OF SOME CHROMIUM SELENIDES - CRYSTAL GROWTH WITH SELENIUM VAPOR AS A NOVEL TRANSPORT AGENT
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DOI：
10.1021/ic50091a032
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发表时间：
1970-01-01
影响因子：
4.6
通讯作者：
ABRAHAMS, SC
中科院分区：
文献类型：
--
作者：
WEHMEIER, FH;KEVE, ET;ABRAHAMS, SC
用化学输运反应生长了三种硒化铬单晶。单斜晶型(M)和三角晶型(T)的近似组分Cr2Se_3分别在10atm和6atm的压力下在硒存在下被输运。非化学计量单晶(‘)使用碘作为运输剂，在约0.8atm的压力下运输ESSe，没有过量的硒。它们的晶格常数分别为a-6.227±0.001 A，b=3.582±0.001，c=11.528±0.002，β=90.77±0.0 1，空间群为I2/m，T相为-12.509±0.002 A，c=34.765±0.005。T‘相也是三方相，a=3.612±0.001，c=5.775±0.002，可能的空间群为P3m1。所有相基本上都是金属空位NiAs结构。空位位于沿c方向的交替金属层中。提出了一些过渡金属硒与硒的输运机制。本文给出了一些过渡金属硫系化合物的简化化学理解，以CrzSe化合物1>；x>；S/S为例，用[CrSe]nn~层之间的n个(1/)或“+”型离子交联键给出了简化的化学理解。
Single crystals of three chromium selenides have been grown by chemical transport reaction. Monoclinic (M) and trigonal (T) forms of approximate composition Cr2Se3 were transported in the presence of selenium only, at pressures of 10 and 6 atm, respectively. Nonstoichiometric single crystals (') of Cro. esSe were transported, without an excess of selenium, using iodine as a transport agent at a pressure ofabout 0.8 atm. TheM phase has lattice constants a— 6.227±0.001 A, b= 3.582±0.001 Á, c= 11.528±0.002 Á, and ß= 90.77±0.01 with space group I2/m. The T phase has a— 12.509±0.002 A and c= 34.765±0.005 Á. The T'phase is also trigonal, with a= 3.612±0.001 Á and c= 5.775±0.002 Á and probable space group P3ml. All phases are basically metal-vacancy NiAs structures. Vacant chromium sites are located in alternate metal layers along c. A mechanism for the transport of some transition metal selenides with selenium is proposed. A simplified chemical understanding of some transition metal chalcogenides, with CrzSe compounds, 1> x> s/s, as an example, is given in terms of n ionic cross-links of type (1/») Or”+ between [CrSe2] nn~ layers.