Half-metallic ferromagnetism in Cr-doped AlP - density functional calculations

First-principles calculations based on spin density functional theory are employed to investigate the ferromagnetic and the spin-resolved electronic properties of Cr-doped AlP. The Cr impurities in AlP are found spin polarized and the calculated band structures suggest a 100% polarization of the conduction carriers. A net magnetic moment of about 3 mu(B) is found per Cr. At a Cr concentration of 12.5%, total energy calculations show that the ferromagnetic state is 108.8 meV per Cr lower than the anti ferromagnetic state and a Curie temperature higher than 650 K can be expected in Cr-doped AIR Both double-exchange and p-d hybridization mechanism contribute to the ferromagnetic ground state of Cr-doped AlP, but the former is dominant. These results suggest that the Cr-doped AlP may be a promising dilute magnetic semiconductor for the applications in the field of spintronics. (C) 2008 Published by Elsevier Ltd.