Phonon instabilities in fcc and bcc tungsten

被引:113
作者
Einarsdotter, K
Sadigh, B
Grimvall, G
Ozolins, V
机构
[1] Department of Theoretical Physics, Royal Institute of Technology, Stockholm
关键词
D O I
10.1103/PhysRevLett.79.2073
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The lattice dynamics of bcc and fcc W is studied as a function of pressure using the density-functional linear-response theory. At high pressures and T = 0 K, bcc W has a higher enthalpy than the fcc and hcp phases and it develops phonon softening anomalies related to this thermodynamic instability; however, it remains dynamically stable. In contrast, the widely unstable shear modes of fcc W at zero pressure (when H-W(fcc) > H-W(bcc)) stabilize with increasing pressure before H-W(fcc) < H-W(bcc). Hence the thermodynamic and dynamic instabilities are uncorrelated.
引用
收藏
页码:2073 / 2076
页数:4
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