First-principles calculations to investigate stability and electronic properties of ferromagnetic (anti-ferromagnetic) semiconducting Heusler alloys Cr2YSi (Cr2YAl)

The phase structure and properties of Heusler alloys Cr2YZ (Z = Al, Si) have been studied using first principles calculations. The L21-type cubic structure found to be energetically preferred to the XA inverse Heusler phase, and with strong ferromagnetic (Cr2YSi) and anti-ferromagnetic (Cr2YAl) properties. Electronic structure and magnetic property calculations predict that Cr2YAl is a semiconducting antiferromagnet. On the other hand, L21-type Cr2YSi shows a high spin polarization and a direct band gap, suggesting promise as a spintronic semiconducting ferromagnet. The effect of tetragonal distortion and Hubbard U correction to exchange-correlation on the physical nature of these alloys are studied and will be discussed. Progress toward experimental realization in bulk or thin film form will also be presented.