Effect of exchange, anisotropy, and external field interactions on the hysteresis and compensation of a two-dimensional ferrimagnet

Abstract

We investigate the effects of exchange, anisotropy, and external field interactions on the of hysteresis and compensation behavior of a two-dimensional ferrimagnet with spins of values Q=7/2, and S=2 alternating on a square lattice, by means of the Monte Carlo (MC) and mean-field (MFT) simulation techniques. We analyze the temperature dependence of the magnetization and the hysteresis loops of the model for various values of the parameters in the Hamiltonian. The system experiences spin compensation, discontinuities, exchange bias, and multiple hysteresis loops when it is subjected to different values of exchange, anisotropy, and magnetic fields. The temperature range where the system experiences discontinuities in the magnetization increases with the decrease (increase) of the |D1′| modulus of the anisotropic field and with the change of direction of the h′ applied field, which is corroborated by the phase diagrams in the (D1′,T) and (h′,T) planes. We found that the exchange bias phenomenon occurs for a threshold value of the next-nearest-neighbor interaction of the S-spin (J2′=7.1). We compare our results with two investigations, one that does not include antiferromagnetic next-nearest-neighbor interactions nor external fields and another that does not consider the anisotropies of the sublattices, which are key parameters in the thermomagnetic behavior of the model.