直接相关函数对双模晶体相场模型相图的影响

研究了直接相关函数峰宽及 k=0处峰对双模晶体相场模型相图的影响. 结果表明, 随着峰宽的增加, 有序相的相区范围不断增大. 而增大峰宽比可使体心立方(bcc)相区范围缩小, 面心立方(fcc)相区范围大幅增加.直接相关函数 k=0峰的引入则使相图被压缩, 两相共存区变窄, 液相稳定区域增加. 关键词： 晶体相场模型 双模近似 相图 直接相关函数

Effect of the direct correlation function on phase diagram of the two-mode phase field crystal model

Effects of the width of direct correlation function peak and the peak at k=0 on the phase diagram for the two-mode phase field crystal model are examined carefully. The results indicate that increasing the width of direct correlation function peak will expand the stability region of the ordered phases; however, increasing the ratio of peak width will significantly increase the fcc phase region but reduce the bcc phase region. Adding a negative Gaussian peak at k=0 to the two-mode approximate direct correlation function will compress the phase diagram and make the two-phase coexisting region narrow.
Keywords： phase field crystal model two-mode approximation phase diagram direct correlation function