Unexpected crystal and magnetic structures in MnCu4In and MnCu4Sn

TitleUnexpected crystal and magnetic structures in MnCu4In and MnCu4Sn
Publication TypeJournal Article
Year of Publication2013
AuthorsProvino A, Paudyal D, Fornasini ML, Dhiman I, Dhar SK, Das A, Mudryk Y, Manfrinetti P, Pecharsky VK
Journal TitleActa Materialia
Volume61
Pages2236-2243
Date Published04
Type of ArticleArticle
ISBN Number1359-6454
Accession NumberWOS:000316241400038
Keywordscopper alloys, CRYSTALLOGRAPHY, ferromagnetic shape memory alloy, Hensler alloys, HEUSLER ALLOYS, magnetic properties, semiconductor spintronics
Abstract

We discovered a new compound MnCu4In with its own hexagonal structure type (hP12-P6(3)mc, ternary ordered derivative of the hexagonal MgZn2-type) that becomes ferromagnetic at T-C = 540 K. This transition temperature is higher than that found in the MnCu2In and MnCu2Sn alloys. In contrast, the homologous compound MnCu4Sn, which crystallizes in the cubic MgCu4Sn-type, orders antiferromagnetically with T-N = 110 K. The neutron diffraction studies show ferromagnetic spin orientation in the {1 0 1} plane in MnCu4In with a magnetic moment of 4.5 mu(B)/Mn at 22 K, and a corresponding value of 4.7 mu(B)/Mn in the antiferromagnetic MnCu4Sn with propagation vector (K) over right arrow = (1/2 1/2 1/2). The first-principles electronic structure calculations show that the unexpected difference in both magnetic and crystal structures of MnCu4In and MnCu4Sn is due to the difference in the Mn-3d bands and exchange interactions relating to different crystal anisotropy, coordination numbers, and interatomic distances. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

URL<Go to ISI>://WOS:000316241400038
DOI10.1016/j.actamat.2012.12.043