A new spin gapless semiconductors family: Quaternary Heusler compounds

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190, PRC
² School of Material Science and Engineering, Hebei University of Technology - Tianjin 300130, PRC

^(a) wenhong.wang@iphy.ac.cn

Received: 20 January 2013
Accepted: 13 March 2013

Abstract

By using first-principles calculations, we investigate the band structures of a series of quaternary LiMgPdSn-type Heusler compounds. Our calculation results show that five compounds, CoFeMnSi, CoFeCrAl, CoMnCrSi, CoFeVSi and FeMnCrSb, possess unique electronic structures characterized by a half-metallic gap in one spin direction while they have a zero-width gap in the other spin direction showing a spin gapless semiconducting behavior. We further analyse the electronic and magnetic properties of all quaternary Heusler alloys involved, and reveal a semi-empirical general rule (the total valence electrons number should be 26 or 28) for indentifying spin gapless semiconductors in Heusler compounds. The influences of lattice distortion and main-group element change have also been discussed.