Ising metamagnets in thin film geometry: equilibrium properties

Abstract

Artificial antiferromagnets and synthetic metamagnets have attracted much attention recently due to their potential for many different applications. Under some simplifying assumptions these systems can be modeled by thin Ising metamagnetic films. In this paper we study, using both the Wang/Landau scheme and importance sampling Monte Carlo simulations, the equilibrium properties of these films. On the one hand we discuss the microcanonical density of states and its prominent features. On the other we analyze canonically various global and layer quantities. We obtain the phase diagram of thin Ising metamagnets as a function of temperature and external magnetic field. Whereas the phase diagram of the bulk system only exhibits one phase transition between the antiferromagnetic and paramagnetic phases, the phase diagram of thin Ising metamagnets includes an additional intermediate phase where one of the surface layers has aligned itself with the direction of the applied magnetic field. This additional phase transition is discontinuous and ends in a critical end point. Consequently, it is possible to gradually go from the antiferromagnetic phase to the intermediate phase without passing through a phase transition.

8 figures, accepted for publication in Physical Review B

References in corpus (5)

• Microcanonical Analyses of Peptide Aggregation Processes
• Continuous phase transitions with a convex dip in the microcanonical entropy
• Microcanonical phase diagrams of short-range ferromagnets
• Monte Carlo investigation of the tricritical point stability in a three-dimensional Ising metamagnet
• Field-driven transition in an Ising magnet with mixed interactions

Cited by in corpus (5)

• Monte Carlo study of the phase diagram of layered XY antiferromagnet
• An entropic simulational study of the spin-$1$ Baxter-Wu model in a crystal field
• Equilibrium and non-equilibrium properties of synthetic metamagnetic films: A Monte Carlo study
• The three-dimensional Baxter-Wu Model
• A Monte Carlo study on the temperature dependence of hysteresis loops in Ising Spin-1 Square Bilayers