Research of magnetocaloric effect of Ni-Mn-In-Co- based Heusler alloys by the direct method in magnetic fields up to 14 T

Abstract

This paper is devoted to the study of magnetocaloric effect (MCE) in Ni-Mn-In-Co Heusler alloys by direct methods in high magnetic fields. Ni-Mn-In-Co Heusler alloys demonstrate the inverse MCE in the magnetostructural transition area. The adiabatic temperature change value ( $\Delta T_{\mathrm {ad}}$ ) is determined by direct extraction method in magnetic fields up to 10 T. It is shown that the value of $\Delta T_{\mathrm {ad}}$ increases with decrease in the difference between the temperature of magnetostructural transition and the Curie point temperatures of the compounds. The amount of isothermal heat emission (sorption) for Ni43Mn37.8In12.2Co7 alloy is determined as a result of magnetization in magnetic field up to 10 T in the magnetostructural transition area. The obtained results are discussed from the viewpoint of magnetic and lattice subsystems influences on the total entropy change ( $\Delta S_{t}$ ).