ELECTRONIC STRUCTURE AND HALF-METALLICITY OF HEUSLER ALLOY Mn2RhAl

Abstract

The site preference, electronic structure and magnetic properties of Mn 2 RhAl have been studied by first-principles calculations. Both the Cu 2 MnAl -structure and the Hg 2 CuTi -type have been tested. For the compound Mn 2 RhAl , the Hg 2 CuTi structure is the more stable one with a lattice parameter of 5.80 Å. The Mn 2 RhAl alloy is predicted to be a half-metal with 100% spin polarization of the conduction electrons at the Fermi level (EF). The calculated total magnetic moment is 2.00 μB per unit cell, which is in line with the Slater–Pauling curve of Mt = Zt-24. The Mn (A) and Mn (B) atom-projected spin moments are -1.54 μB and 3.16 μB, respectively. The resulting moment is mainly determined by the antiparallel aligned Mn (A) and Mn (B) spin moment. Whereas, the small spin magnetic moment of Rh is small and only 0.38 μB and the Al atom is almost nonmagnetic. Such an alloy may be a promising material for future spintronics devices.