原子与分子物理学报Issue(3)：473-480,8.DOI:10.3969/j.issn.1000-0364.2015.03.022
外压下 VN 相变和力学性质的第一性原理研究
First principles study on phase transformation and mechanical properties of VN under external pressure
摘要
Abstract
The structure, elastic properties and phonon dispersion relation of VN under high pressure are studied by using density functional program VASP, Quantum ESPRESSO and Phonopy package.Three configurations of NaCl (B1), CsCl (B2) and WC (Bh) phases of VN are investigated, respectively.The volume energy curve, enthalpy-pressure relation and phonon spectrum show that the hexagonal WC structure is more stable compared with the cubic structures at atmospheric pressure.With the increase in pressure we find that the phase transition of VN from Bh structure to B1 structure may occur at about 30 GPa and that from B1 structure to B2 structure at about 150 GPa.The three kinds of VN are mechanical stable at ambient pressure, the elastic constants and elas-tic moduli increase with the increasing pressure.Three kinds of VN are brittle materials.The Young′s modulus values on the B1 and B2 structure coordinates structural basis vector directions differ significantly from those on the body diagonal direction and show obvious anisotropy.The anisotropy of B1 structure increases, while that of B2 structure decreases with the increase in pressure.关键词
VN/相变/高压/力学性质/第一性原理Key words
VN/Phase transition/High pressure/Mechanical properties/First-principles分类
数理科学引用本文复制引用
谭心,穆庆鸽,王洋洋,刘学杰..外压下 VN 相变和力学性质的第一性原理研究[J].原子与分子物理学报,2015,(3):473-480,8.基金项目
内蒙古自然科学基金（2009MS0812）；内蒙古自治区高等学校研究项目（ NJ10103， NJZY153）；内蒙古科技大学创新基金 （）
