Heusler clusters

ORAL

Abstract

Heusler alloys are known for their bulk properties, for example the magnetic shape-memory Ni$_2$MnGa [1]. Using first principles simulations, based on the real space pseudopotential method implemented in PARSEC [2], we examine Heusler alloy clusters. Clusters with various Ni-Mn-Ga compositions are examined in the size from 15 up to 113 atoms. Clusters with compositions being the closest to the stoichiometric Ni$_2$MnGa are the most stable. The geometry of tetrahedral coordination in Heusler structures is energetically favorable. In order to retain this coordination, clusters have to be symmetrically shaped. This implies that even in very small clusters the structure is bulk-like. However, the electronic densities of states do not show Kohn-like anomalies at the Fermi level, that are characteristic for bulk Ni-Mn-Ga alloys. [1] P. Entel, V. D. Buchelnikov, V. V. Khovailo et al. J. Phys. D: Appl. Phys. 39, 865 (2006) [2] http://www.ices.utexas.edu/parsec/

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Authors

  • Alexey Zayak

    ICES, University of Texas at Austin

  • Murilo L. Tiago

    University of Texas at Austin, University of Minnesota, ICES, University of Texas at Austin

  • Scott Beckman

    University of Texas, ICES, University of Texas at Austin

  • James R. Chelikowsky

    University of Texas, University of Texas at Austin, ICES, University of Texas at Austin