Modélisation et simulation de l’effet magnétocalorique dans les matériaux Full Heusler inverse à base de terre rare.

Abstract

Over the past 20 years, research on the magneto-caloric response of materials has grown considerably, mainly due to the possibility of applying this effect to magnetic refrigeration close to ambient temperature. This study is devoted to the main families of materials suitable for this application and the procedures proposed to predict their response. The magnetic, structural, electronic and thermodynamic properties of inverse Heusler alloys were studied using first principle calculations and mean field theory. To achieve this objective, we first used the Ab initio method to determine the state densities of the compound and the magnetic properties from which it was found that the magnetic results of the Rh2PrIn compound are of the ferromagnetic type, with a magnetic moment about 2.0867 μB for the element Pr .On the other hand, we established the thermodynamic properties and the magnetocaloric effect of the compound in question by the mean field simulation method within the framework of the Ising spin model S=1/2 where a program was developed in Fortran and Python, Therefore, we have obtained a number of results such as the determination of magnetization, critical temperature and behaviour of magnetization isotherms to a magnetic field applied for our alloy. The approximation of the mean field presents a second-order transition and also shows the presence of the ferromagnetic order in the fundamental state, which is in good agreement with the calculations of the first principle