Magnetocaloric effect and magnetization in a Ni-Mn-Ga Heusler alloy in the vicinity of magnetostructural transition

摘要

The magnetic and thermodynamic properties of a Ni2.19Mn0.81Ga alloy withcoupled magnetic and structural (martensitic) phase transitions were studiedexperimentally and theoretically. The magnetocaloric effect was measured by adirect method in magnetic fields 0-26 kOe at temperatures close to themagnetostructural transition temperature. For theoretical description of thealloy properties near the magnetostructural transition a statistical model issuggested, that takes into account the coexistence of martensite and austenitedomains in the vicinity of martensite transformation point.