【摘要】 利用分子动力学模拟结果研究了SiO2 、GeO2 和α -AlPO4系统高压下相变的可逆转性问题。SiO2 和GeO2 系统高压下的相变非常类似 ,仅稍有差别。SiO2 和GeO2 系统高压下形成的新相 ,去除压力后在常压下仍可稳定存在。α-AlPO4系统高压下的相变不同于SiO2 和GeO2 系统 ,其高压下的新相在常压下又回复到原来结构。分析模拟数据 ,找到了存在差别的七个方面 ,即压缩性、配位数、键长、亚稳态 ,熵变、玻璃转变温度和各向异性。讨论了高压下相变的可逆转性与前五个方面的关系。用重构型相变和位移型相变很好解释了上述差别。更多还原

【Abstract】 The reversibility of Phase transition in SiO 2、GeO 2 and α-AlPO 4 Systems under high Pressure was studied with the aid of the results of molecular dynamics simulation.Pressure-induced amorphization has been observed in a variety of materials,including SiO 2、GeO 2、α-AlPO 4.In some cases(SiO 2、GeO 2) the amorphous phase is retained on reducing the Pressure to 0.1MPa,while in others (α-AlPO 4),the amorphous solid reverts to the Crystalline form on reducing the Pressure to 0.1 MPa.There are seven aspects differing from each other system.The relation between the reversibility of phase transition and the differences was discussed.The explanation was given.更多还原