Study of magnetic field influence on magnetization distribution in three-layer ferromagnetic-antiferromagnetic spin systems

Abstract

In the paper three-layer spin systems from two ferromagnetic films separated by an antiferromagnetic film are examined. These systems are used in spintronics devices. Films described by the Ising model are considered. Ferromagnetic films are made of different materials. One ferromagnetic film is magnetic soft, the second is magnetically hard. The behavior of the system in the external magnetic field has been investigated. Computer simulation is performed using the Metropolis algorithm. Each film has its own order parameter. The finite dimension scaling theory is used to define model parameters. Systems with different ratio of exchange integrals are considered. The phase transition temperature was determined for each films using Binder cummulants. A phase diagram of the system is built at different ratios of exchange integrals. Phases have been identified that can be used in the design of spintronics devices. The phase transition temperature was found to be dependent on the film thickness. The magnetic field for magnetization switching of a soft magnetic film is determined as a function on temperature and the exchange integral. The maximum magnetic field for changing magnetization only one film is calculated. It is shown that as the temperature increases, the value of the minimum magnetic field for magnetization switching decreases. An increase in exchange integral value leads to an increase in the minimum value for magnetization switching magnetic field. For thin films, the dependence of the minimum magnetic field strength is weakly dependent on the film thickness. The values of the studied magnetic fields are considerably less than the limit magnetic field for the antiferromagnetic film and do not lead to suppression of the antiferromagnetic order.