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

Abstract

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.