Magnetocaloric effect and its relation to shape-memory properties in ferromagnetic Heusler alloys

• Published in: Journal of physics. Condensed matter 2009-06, Vol.21 (23), p.233201-233201 (29)
• Main Authors: Planes, Antoni, Mañosa, Lluís, Acet, Mehmet
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Elasticity, elastic constants; Exact sciences and technology; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetocaloric effect, magnetic cooling; Martensitic transformations; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/21/23/233201

Magnetic Heusler alloys which undergo a martensitic transition display interesting functional properties. In the present review, we survey the magnetocaloric effects of Ni-Mn-based Heusler alloys and discuss their relation with the magnetic shape-memory and magnetic superelasticity reported in these materials. We show that all these effects are a consequence of a strong coupling between structure and magnetism which enables a magnetic field to rearrange martensitic variants as well as to provide the possibility to induce the martensitic transition. These two features are respectively controlled by the magnetic anisotropy of the martensitic phase and by the difference in magnetic moments between the structural phases. The relevance of each of these contributions to the magnetocaloric properties is analysed.