【摘要】 利用从头算分子动力学方法研究了BeO的高压诱导相变,发现,在360GPa压强下纤锌矿(WZ)结构的BeO平稳地相变为岩盐(RS)结构,且没有经过闪锌矿(ZB)结构。相变机制包含模拟胞的单斜变形、沿[2110]方向的原子膨胀以及沿[0110]和[0001]方向的原子收缩。比较研究了闪锌矿(ZB)结构BeO的高压诱导相变。在160 GPa压强下观察到ZB结构的BeO在相变为RS结构之前经过了四角的和单斜的中间相,与其它ZB结构材料在高压下的相变路径一致。更多还原

【Abstract】 Ab initio molecular dynamics method has been used to study high pressure-induced phase transformation in BeO.It is shown that at 360 GPa the wurtzite(WZ) BeO transforms to rocksalt(RS) structure smoothly without passing through the zinc blende(ZB) phase.The transformation mechanism involves a monoclinic deformation of the simulation cell,and the atoms expanding along the[2110]direction and contracting along the[0110]and [0001]directioa High pressure-induced phase transformation in ZB BeO was also studied for comparisoa It was observed that at 160 GPa the ZB BeO passes through a tetragonal and a monoclinic intermediate phases before transformation to RS structure,consistent with the transformation pathway of other ZB-structured materials under high pressure.更多还原