Magnetization behavior and magnetic entropy change of frustrated Ising antiferromagnets on two- and three-dimensional lattices

Abstract

The magnetization behavior and the magnetic entropy change of frustrated Ising antiferromagnets with spin-1/2 on two-dimensional triangular and three-dimensional hexagonal closed-packed lattices are calculated by using Monte Carlo simulation. The results indicate that the normalized magnetization as a function of external field shows a 1/3 plateau on the two-dimensional system, while it shows 0 and 1/2 plateaus on the three-dimensional system at low temperature. Consequently, it causes an inverse magnetocaloric effect, namely, the value of magnetic entropy change may be positive in some ranges of magnetic fields. This phenomenon may be used to cool in a field by adiabatic demagnetization. Moreover, we analyze the spin configurations of systems on the magnetization plateaus, and discuss the impact of the frustration. We also find a mapping of the magnetization plateaus to the magnetic entropy changes at low temperature. The study of such systems showing field-induced metamagnetic transition in relation to frustrated antiferromagnets may open an important field in searching for good candidates for room-temperature magnetic refrigeration.