The effect of anisotropic field on magnon numbers, magnetization and heat capacity of antiferromagnetic materials

Abstract

This article provides a theoretical examination of the impact of anisotropic fields on the magnetization and heat capacity thermodynamic properties of sublattice antiferromagnetic spin systems. The analysis begins with the classical Heisenberg model and considers uniaxial anisotropic fields in the antiferromagnetic system. Quantum field theory and the double time temperature dependent Green’s function technique, which incorporates the random phase approximation, are used to decouple and diagonalize the higher order terms. The study utilizes a dispersion of uniaxial symmetric AFM crystal lattice to examine the thermodynamic parameters of magnetization and heat capacity as a function of excitation temperature at low temperatures and long wavelength approximation. The results demonstrate that the magnetization and heat capacities of AFM are sensitive to anisotropic fields, with the magnetization deviation moving up and the heat capacity maximum peak reducing with increased anisotropy. These findings may have implications for the use of antiferromagnetic materials with similar anisotropy sources and stability in real-world applications.