Local Atomic Structure of Martensitic Ni$_{2+x}$Mn$_{1-x}$Ga: An EXAFS Study

P. A. Bhobe; K. R. Priolkar; P. R. Sarode

doi:10.1103/PhysRevB.74.224425

Local Atomic Structure of Martensitic Ni$_{2+x}$Mn$_{1-x}$Ga: An EXAFS Study

Materials Science 2009-11-11 v1

Authors: P. A. Bhobe , K. R. Priolkar , P. R. Sarode

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Abstract

The local atomic structure of Ni $_{2+x}$ Mn $_{1-x}$ Ga with 0 $\le$ $x$ $\le$ 0.16 alloys was explored using Mn and Ga K-edge Extended X-ray Absorption Fine Structure (EXAFS) measurement. Inorder to study the atomic re-arrangements that occur upon martensitic transformation, room temperature and low temperature EXAFS were recorded. The changes occurring in the L2 $_1$ unit cell and the bond lengths obtained from the analysis enables us to determine the modulation amplitudes over which the constituent atoms move giving rise to shuffling of the atomic planes in the modulated structure. The EXAFS analysis also suggests the changes in hybridization of Ga- $p$ and Ni- $d$ orbitals associated with the local symmetry breaking upon undergoing martensitic transition.

Keywords

Hubbard model ferromagnetism Goldstone mode lattice effects band dispersion

Cite

@article{arxiv.cond-mat/0611237,
  title  = {Local Atomic Structure of Martensitic Ni$_{2+x}$Mn$_{1-x}$Ga: An EXAFS Study},
  author = {P. A. Bhobe and K. R. Priolkar and P. R. Sarode},
  journal= {arXiv preprint arXiv:cond-mat/0611237},
  year   = {2009}
}

Comments

Accepted for publication in Physical Review B

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