The Influence of a Magnetic Field on Phase Transition in Antiferromagnetic Films: Computer Modeling Research

Resumo

The influence of an external magnetic field on the phase-transition temperature for antiferromagnetic thin films is investigated. The computer modeling method for the antiferromagnetic Ising model with a thin film geometry is used. Films with thicknesses from 4 to 16 layers have been investigated. It is shown that the temperature of the antiferromagnetic phase transition decreases according to the square law as the external magnetic intensity increases. The rate of decrease of the phase-transition temperature depends on the film thickness and on the relationship between the exchange integrals on the surface and the bulk of the system. For each system, there is a limit value of the magnetic intensity such that no antiferromagnetic phase transition occurs if it is exceeded. The dependence of the limit value of the magnetic intensity on the relationship between the exchange integrals obeys the square law as well.