PdZn or ZnPd: Charge Transfer and Pd-Pd Bonding as the Driving Force for the Tetragonal Distortion of the Cubic Crystal Structure
PdZn or ZnPd: Charge Transfer and Pd-Pd Bonding as the Driving Force for the Tetragonal Distortion of the Cubic Crystal Structure
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DOI：
10.1002/zaac.201000097
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发表时间：
2010-01-01
影响因子：
1.4
通讯作者：
Armbruester, Marc
中科院分区：
文献类型：
--
作者：
Friedrich, Matthias;Ormeci, Alim;Armbruester, Marc
据报道，金属间化合物PdZn具有两种变型，即四方CuAu型低温相和立方CsCl型高温相。在等原子组成时，立方高温相的存在无法从实验上得到证明。对总能量的计算表明，在c/a=1.155处有一个极小值，这清楚地排除了Pd-Zn系统中等原子组成的立方结构。用电子局域化方法对化学键的分析揭示了锌向钯的电荷转移，并证明了Pd-Pd在(001)面上的直接Pd-Pd相互作用是导致ZnPd的立方CsCl型结构图案发生四方扭曲的主要原因。
The intermetallic compound PdZn was reported to have two modifications, the tetragonal CuAu-type low-temperature phase and the cubic CsCl-type high-temperature phase. The existence of the cubic high-temperature phase at the equiatomic composition could not be proven experimentally. Calculations of the total energy reveal a minimum at c/a = 1.155, clearly excluding the cubic structure at the equi-atomic composition ill the system Pd-Zn. Analysis of the chemical bonding applying the electron localizability approach reveals charge transfer from zinc to palladium and proves direct Pd-Pd interactions in the (001) plane to be the main reason for the tetragonal distortion of the cubic CsCl-type structural pattern for ZnPd.