Volume 80, Number 5, December 2007
Article Number 57002
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 30 October 2007
EPL, 80 (2007) 57002
DOI: 10.1209/0295-5075/80/57002

Martensitic transition, ferrimagnetism and Fermi surface nesting in Mn2NiGa

S. R. Barman1, S. Banik1, A. K. Shukla1, C. Kamal2 and Aparna Chakrabarti2

1  UGC-DAE Consortium for Scientific Research - Indore, 452017, Madhya Pradesh, India
2  Raja Ramanna Centre for Advanced Technology - Indore, 452013, Madhya Pradesh, India

received 7 August 2007; accepted in final form 5 October 2007; published December 2007
published online 30 October 2007

The electronic structure of Mn2NiGa has been studied using density functional theory and photoemission spectroscopy. The lower-temperature tetragonal martensitic phase with c/a = 1.25 is more stable compared to the higher-temperature austenitic phase. Mn2NiGa is ferrimagnetic in both phases. The calculated valence band spectrum, the optimized lattice constants and the magnetic moments are in good agreement with experiment. The majority-spin Fermi surface (FS) expands in the martensitic phase, while the minority-spin FS shrinks. FS nesting indicates occurrence of phonon softening and modulation in the martensitic phase.

71.20.Be - Transition metals and alloys.
71.18.+y - Fermi surface: calculations and measurements; effective mass, g factor.
81.30.Kf - Martensitic transformations.

© Europhysics Letters Association 2007