Проявление фрустраций основного состояния двумерной разбавленной модели Изинга в магнитокалорическом эффекте

Abstract

The magnetocaloric effect is considered in the 2D dilute Ising model for various ratios of the parameters of inter-site repulsion of nonmagnetic impurities and exchange interaction. Numerical simulations using the classical Monte Carlo method on a square lattice shows that in the case of weak exchange at sufficiently high concentrations of nonmagnetic impurities, long-range ferromagnetic ordering is destroyed with the formation of isolated spin clusters in the ground state of the system. This leads to the appearance of a paramagnetic response of the system at zero temperature and a nonzero entropy of the ground state. In the paper, we discuss the possibility of detecting the frustration of the ground state using data on changes in magnetic entropy.