High-T C fully compensated ferrimagnetic semiconductors as spin-filter materials: the case of CrVXAl (X = Ti, Zr, Hf) Heusler compounds

Abstract

We extend our recent work on spin-filter materials (Galanakis et al 2013 Appl. Phys. Lett.103 142404) to the case of CrVXAl (X = Ti, Zr, Hf) compounds, for which, using ab initio electronic structure calculations, we show that p–d hybridization leads to the formation of a fully compensated ferrimagnetic semiconducting state with moderate exchange splitting. The magnetism is of covalent-type and the very strong antiferromagnetic Cr–V exchange interactions lead to extremely high Curie temperature, TC, values. Furthermore, all three compounds are thermodynamically and magnetically stable. The combination of very high TC values with a zero total net magnetization makes them promising materials for spintronics applications.