Fermi surface nesting and pre-martensitic softening in V and Nb at high pressures
Fermi surface nesting and pre-martensitic softening in V and Nb at high pressures
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DOI：
10.1088/0953-8984/18/22/008
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发表时间：
2006-06-07
影响因子：
2.7
通讯作者：
Ruban, A.
中科院分区：
文献类型：
--
作者：
Landa, A.;Klepeis, J.;Ruban, A.
用第一性原理计算了体心立方V和Nb的三角剪切弹性常数C-44。在C44中的机械不稳定性被发现为V在类似于2兆巴的压力，这也表明在Nb软化在类似于0.5兆巴的压力。我们认为，压力诱导的剪切不稳定性（软化）的V（Nb）是由于带内嵌套的费米面。
First-principles total-energy calculations were performed for the trigonal shear elastic constant (C-44) of body-centred cubic (bcc) V and Nb. A mechanical instability in C44 is found for V at pressures of similar to 2 Mbar which also shows a softening in Nb at pressures of similar to 0.5 Mbar. We argue that the pressure-induced shear instability (softening) of V (Nb) is due to the intra-band nesting of the Fermi surface.