无规场非晶化表面的临界行为

CRITICAL BEHAVIOR AT THE SURFACE OF A SEMI\|INFINITE MIXED\|SPIN ISING SYSTEM WITH SURFACE RANDOM FIELD AND AMORPHISM

应用平均场重整化群方法，讨论表面无规场和非晶化存在对 Ｓ＝ １ 和 σ＝ １／２ 混合自旋伊辛系统表面磁性临界行为的影响，得到在各种情况下系统的表面相图．计算结果表明，非晶化在一定范围内与无规场竞争仍可出现三临界点和重入现象．

In this paper,a renormalization group scheme within the framework of the mean field theory is used to investigate the critical behavior at the surface of a semi\|infinite Ising system with mixed spins,i.e., S =1 at the surface and σ =1/2 in the bulk.The effects of the random field and amorphism on the surface phase diagrams are obtained and discussed.The numerical results show that the surface tricritical points and reentrant phenomena exist due to the competition between the surface random field and certain magnitude of surface amorphization. PACC: 7510H; 7530T; 7540