Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
Inorg Chem. 2010 Aug 16;49(16):7491-6. doi: 10.1021/ic100790r.
A new caged Cu-rich antimonide, BaCu(7.31(3))Sb(5), was obtained from a direct combination of the elements in a graphite crucible under a high vacuum by a solid state reaction, and the structure was determined by the single-crystal X-ray diffraction method to be hexagonal P6(3)/mmc (No.194), with a = 7.0154(4) A, c = 12.5423(14) A, V = 534.58(7) A(3), and Z = 2. BaCu(7.31(3))Sb(5) is the first antimonide member of the BaNi(9)P(5)-type barium copper pnictides with a Cu2 site occupancy of 43.7(9)%, and the structure building unit is a 30-vertex Cu(18)Sb(12) cage centered by a Ba atom. The Cu(18)Sb(12) cages form chains along the c axis by sharing the opposite hexagonal (Cu2)(3)(Sb2)(3) faces. Such a cage chain shares (Cu1)(2)(Sb1)(2) rhomboidal faces with six neighboring chains along the [100], [010], and [110] directions to generate a 3D condensed metallic network. The electronic structure calculations by CASTEP indicate the metallic nature, which matches well with the metallic electrical conductivity, small Seebeck coefficient, and Pauli paramagnetism. The calculated formation energies indicate that BaCu(7.5)Sb(5)[triple bond]Ba(2)Cu(15)Sb(10) with the Cu2 site half occupied is the energetically favorable stoichiometry compared with Ba(2)Cu(12)Sb(10) (empty Cu2 site) and Ba(2)Cu(18)Sb(10) (fully occupied Cu2 site).
一种新的笼状富铜锑化物 BaCu(7.31(3))Sb(5) 是通过元素在高真空下的石墨坩埚中的直接组合，通过单晶 X 射线衍射法确定其结构为六方 P6(3)/mmc(No.194)，空间群，a = 7.0154(4)A，c = 12.5423(14)A，V = 534.58(7)A(3)，Z = 2。BaCu(7.31(3))Sb(5) 是 BaNi(9)P(5)- 型钡铜磷化物中第一个锑化物成员，Cu2 位占据率为 43.7(9)%，结构构建单元是以 Ba 原子为中心的 30 个顶点的 Cu(18)Sb(12)笼。Cu(18)Sb(12)笼通过共享相反的六边形(Cu2)(3)(Sb2)(3)面沿 c 轴形成链。这样的笼链沿[100]、[010]和[110]方向与六个相邻链共享(Cu1)(2)(Sb1)(2)菱形面，生成一个三维凝聚金属网络。CASTEP 的电子结构计算表明其具有金属性质，这与金属电导率、小的塞贝克系数和泡利顺磁性质吻合良好。计算的形成能表明，与 Ba(2)Cu(12)Sb(10)(空的 Cu2 位)和 Ba(2)Cu(18)Sb(10)(满的 Cu2 位)相比，具有半占据 Cu2 位的 BaCu(7.5)Sb(5)[三重键]Ba(2)Cu(15)Sb(10)是能量上有利的化学计量比。
