直接相关函数对双模晶体相场模型相图的影响

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

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.

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.