Atomic diffusion in covalent liquids under pressure from ab initio molecular dynamics
Atomic diffusion in covalent liquids under pressure from ab initio molecular dynamics
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从头开始分子动力学压力下共价液体中的原子扩散
DOI：
10.1051/epjconf/20111502003
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发表时间：
2011
影响因子：
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通讯作者：
Satoshi Ohmura
中科院分区：
文献类型：
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作者：
倉鋪圭太;永田純平;深尾隆則;開田宏介;倉鋪圭太;倉鋪圭太;Hajime Inaba;稲葉肇;Fuyuki Shimojo;Satoshi Ohmura
用从头算分子动力学方法研究了GeO2和SrGeO3中原子扩散的微观机制。阐明了液态GeO2和SrGeO3扩散机制的差异。在这两种液体中，非桥氧双键键合到只有一个锗酸盐在原子扩散机制中起着关键作用。结果表明，在常压下平衡态存在非桥氧的液态SrGeO3中，在常压下原子扩散是可能的而不会产生过配位原子，而在液态GeO2中非桥氧的形成总是需要过配位原子.当压力增加时，只有液态GeO 2具有扩散最大值，其由下式给出，原子扩散与协同反应给出扩散最大值。
The microscopic mechanisms of atomic diffusion in liquid GeO2and SrGeO3are investigated byab initiomolecular-dynamics simulations. We clarify the differences of diffusion mechanism between liquid GeO2and SrGeO3. In both liquids, non-bridging oxygen double bonded to only one germanate plays a key role in the atomic diffusion mechanism. It is found that, in liquid SrGeO3which has non-bridging oxygen in the equilibrium state at ambient pressure, atomic diffusion is possible without generating overcoordinated atoms at ambient pressure, while the over coordinated atoms are always needed for the formation of non-bridging oxygens in liquid GeO2. When the pressure increases, only liquid GeO2has a diffusion maximum, which is given by, the atomic diffusion with concerted reaction gives the dif fusion maximum.