Normal and inverse magnetocaloric effect in magnetic multilayers with antiferromagnetic interlayer coupling

TL;DR

This study investigates the magnetocaloric effects in magnetic multilayers with antiferromagnetic coupling, revealing conditions for normal and inverse effects and their dependence on interaction parameters and magnetic compensation.

Contribution

It introduces a detailed thermodynamic analysis of multilayer systems with arbitrary anisotropic couplings, highlighting the conditions for magnetocaloric effects and magnetic compensation.

Findings

Identified parameter ranges for normal and inverse magnetocaloric effects.

Linked magnetocaloric behavior to magnetic compensation phenomena.

Provided phase diagrams illustrating magnetic states and effects.

Abstract

The thermodynamics of a spin-1/2 magnetic multilayer system with antiferromagnetic interplanar couplings is studied using the Pair Approximation method. The special attention is paid to magnetocaloric properties, quantified by isothermal entropy change. The multilayer consists of two kinds of magnetic planes, one of which is diluted. The intraplanar couplings in both planes have arbitrary anisotropy ranging between Ising and isotropic Heisenberg interactions. The phase diagram related to the occurrence of magnetic compensation phenomenon is constructed and discussed. Then the isothermal entropy change is discussed as a function of interaction parameters, magnetic component concentration and external magnetic field amplitude. The ranges of normal and inverse magnetocaloric effect are found and related to the presence or absence of compensation.