First principles study of HfV₂ and ZrV₂ phases: Structural analysis and site preference of Cd and Ta dopants

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• 作者：Jana Radaković ; ; ^{janar@vinca.rs} ; Jelena Beloš ; ević ; -Č ; avor ^{cjeca@vinca.rs} ; Vasil Koteski ^{vkotes@vinca.rs}
• 关键词：A. Laves phases ; B. Electronic structure of metals and alloys ; D. Defects ; point defects ; D. Site occupancy ; E. Electronic structure ; calculation
• 刊名：Intermetallics
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：32
• 期：Complete
• 页码：90-95
• 全文大小：851 K

文摘

We present first principles calculations of the electric field gradients (EFGs) in the pure cubic, tetragonal and orthorhombic phases of HfV₂ and in the cubic phase of ZrV₂. Band structure calculations of orthorhombic and tetragonal HfV₂ are presented for the first time. EFGs are also calculated on the inserted Ta and Cd probe atoms, and results are compared with the existing experimental data from time differential perturbed angular correlations and nuclear magnetic resonance measurements. By this comparison, it was possible to determine the exact space group and crystallographic positions of orthorhombic HfV₂, and the site preferences of the Ta and Cd probe atoms. We have also confirmed that the measured nonzero EFG in the Ta-doped cubic HfV₂ structure originates from the displacement of Ta atoms from their equilibrium positions in the cubic environment.