Magnetocaloric Effect and Magnetic Properties of the Intermetallic Compound Mn5Ge3: Ab Initio Calculation and Monte Carlo Simulation

Abstract

AbstractThe Magnetocaloric effect (MCE) is a physical phenomenon that occurs in magnetic materials under the influence of a varying magnetic field. Is it usually expressed as the adiabatic temperature change or isothermal total entropy change of a material. For room temperature cooling, one utilizes that the magnetocaloric effect peaks near magnetic phase transitions and so the materials of interest all have a critical temperature within the range of 250−310 K. It is worth noting that from a practical point of view, the Suitable magnetocaloric material must exhibit a large MCE under relatively low magnetic fields (<2 T) that can be reached via permanent Magnets. Particularly, the Mn5Ge3 Based compounds offer key advantages for application in magnetic refrigeration when compared with the reference Gadolinium metal such as their low cost. In fact, for a large-scale commercialization of this emerging technology, the Gd is unfavourable because of rising prices of rare earths while the intermetallic Mn5Ge3 is completely composed of abundant and affordable elements. In this work, we investigated the magnetic properties as well as the electronic structure of the Mn5Ge3 compound using the density functional theory. The magnetocaloric properties in terms of both adiabatic temperature and magnetic entropy changes were determined using the Monte Carlo approach, while the thermodynamic performances were simulated according to the active magnetic refrigeration (AMR).KeywordsMagnetocaloric effectMonte Carlo simulationActive magnetic refrigerationDensity functional theoryAb initio calculation