A theoretical study of the electronic, magnetic and magnetocaloric properties of the TbMnO3 multiferroic

Abstract

During the last years, a great attention has been devoted to the discovery of materials that can be used for magnetocaloric applications such as intermetallics and oxides. In this context, the multiferroic TbMnO3 appears as promising magnetocaloric material that can be used for magnetic refrigeration at low temperatures. This multiferroic presents complex electronic and magnetic structures. In this paper, different approaches are used with the aim to get more insight on the driving mechanisms behind the electronic, magnetic and magnetocaloric properties of the TbMnO3 manganite. In this way, a physical model is proposed to describe the magnetic interaction inside this material. Using the density functional theory, the electronic structure, density of states, have been evaluated. The magnetic phase stability and exchange couplings in TbMnO3 have been also investigated in order to understand and to clarify the obscured different magnetic interaction in this compound. Magnetocaloric and magnetic properties have been studied using Monte Carlo Simulation (MCS) within the Ising model. The transition temperatures, the isothermal magnetic entropy change, the adiabatic temperature change and the relative cooling power (RCP) were calculated. The highest obtained isothermal entropy change is found to be −17.8 J/Kg.K for H = 8 T. The RCP maximum value is found to be 507.06 J/Kg and the adiabatic temperature change reaches a maximum value close to 22.5 K in the field change of H = 8 T.