Eur. Phys. J. B (2013) 86: 65
https://doi.org/10.1140/epjb/e2012-30936-9

Regular Article

Complex magnetic ordering as a driving mechanism of multifunctional properties of Heusler alloys from first principles^*

¹ Faculty of Physics and CENIDE, University of Duisburg-Essen, 47048 Duisburg, Germany
² Department of Mechanical Engineering, Texas A&M University, College Station, 77843 Texas, USA
³ National University of Science and Technology ‘MISIS’, 119049 Moscow, Russia
⁴ Condensed Matter Physics Department, Chelyabinsk State University, 454001 Chelyabinsk, Russia
⁵ IMEM Department of Magnetic Materials, CNR, Parco delle Scienze 37/a, 43010 Parma, Italy
⁶ Dipartimento Chimica GIAF, Università di Parma, 43124 Parma, Italy
⁷ Universidad del Pais Vasco, Departamento de Electricidad y Electronica, P.O. Box 644, 48080 Bilbao, Spain
⁸ Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain

^a e-mail: entel@thp.uni-duisburg.de

Received: 12 October 2012
Received in final form: 12 December 2012
Published online: 20 February 2013

Abstract

First-principles calculations are used to study the structural, electronic and magnetic properties of (Pd, Pt)-Mn-Ni-(Ga, In, Sn, Sb) alloys, which display multifunctional properties like the magnetic shape-memory, magnetocaloric and exchange bias effect. The ab initio calculations give a basic understanding of the underlying physics which is associated with the complex magnetic behavior arising from competing ferro- and antiferromagnetic interactions with increasing number of Mn excess atoms in the unit cell. This information allows to optimize, for example, the magnetocaloric effect by using the strong influence of compositional changes on the magnetic interactions. Thermodynamic properties can be calculated by using the ab initio magnetic exchange parameters in finite-temperature Monte Carlo simulations. We present guidelines of how to improve the functional properties. For Pt-Ni-Mn-Ga alloys, a shape memory effect with 14% strain can be achieved in an external magnetic field.