Magnetocaloric effect in ternary ErAgAl: Ab initio, mean field and Monte Carlo approaches

Abstract

ErAgAl has been known as an orthorhombic system of the CeCu2-type with ferromagnetic ground state. In this work, the magnetic and magnetocaloric effect has been studied using first principles calculations, Monte Carlo and Mean Field approaches. The adiabatic temperature change, the isothermal entropy change, and the relative cooling power (RCP) have been calculated. The Erbium magnetic moment calculated by FP-LAPW method is 8.21μB, in good agreement with experimental data. The compound exhibits a second order phase transition from paramagnetic to ferromagnetic state at Tc = 14 K. The isothermal entropy change (-ΔSMmax) reaches a maximum value equal to −12.24 J Kg−1 K−1 for a magnetic field of 6 T showing a large magneto-caloric effect around the Curie temperature with no obvious thermal and magnetic hysteresis loss in good agreement with experimental data. The obtained results make the compound suitable for magnetic refrigeration at low temperature regime. Keywords: Magneto-caloric effect, Relative cooling power, Electronic structure, Monte Carlo simulation, Ferromagnetis