APPLICATION OF MICROCANONICAL TEMPERATURE TO THE SPIN CROSSOVER OF Fe-Co COMPOUNDS

Abstract

Using the Rugh’s microcanonical approach to temperature we study the classical model of three dimensional spin-crossover of Fe-Co compounds. These compounds are characterized by magnetic ions that can be in a high-spin or low-spin state. We consider the case of diamagnetic low-spin state. The values of the magnetization average, and fraction of high-spin/low-spin are studied over a wide range of values for the system size, temperature, magnetic field, energy difference, nearest neighbor coupling and exchange interaction. We also address the metastability according to the relative values of interaction parameters and the phase diagram of the model.

Keywords: phase transition, dynamical temperature, spin crossover