Magnetic anisotropy in Ni2MnGa

J. Enkovaara, Lars Nordström, R.M Nieminen

Research output: Contribution to journalArticleScientificpeer-review

79 Citations (Scopus)
66 Downloads (Pure)

Abstract

We study here, within the density-functional theory, the magnetic anisotropy energy (MAE) in Ni2MnGa which is a prototype of a magnetic shape-memory alloy. We calculate the MAE, which is a key property for the magnetic shape-memory effect, for tetragonal structure with different ratios of the c and a lattice constants, reproducing the experimental easy axes both in compression and elongation of the structure. Good agreement between the theory and the experiments in the actual values of the MAE is also found when the nonstoichiometry of the experimental samples is modeled with a simple rigid band approximation. In addition, we estimate the magnetostriction coefficient, confirming the difference between the ordinary magnetostriction and the magnetic shape-memory effect. Equally important, we study the microscopic origin of the MAE in Ni2MnGa with the spin density and the orbital moment anisotropy and extend the analysis of the orbital moment anisotropy to the ternary compounds. These results show that the largest contribution to the MAE comes from Ni, in spite of the larger magnetic moment in the Mn sites.
Original languageEnglish
Article number134422
Pages (from-to)1-7
JournalPhysical Review B
Volume65
Issue number13
DOIs
Publication statusPublished - 2002
MoE publication typeA1 Journal article-refereed

Keywords

  • density functional theory
  • magnetic anisotropy
  • magnetic shape memory effect

Fingerprint Dive into the research topics of 'Magnetic anisotropy in Ni2MnGa'. Together they form a unique fingerprint.

Cite this