First principles and Monte Carlo study of Mn-doped CuCl/CuBr as room-temperature ferromagnetism materials

The magnetic properties of Mn-doped CuCl and CuBr are investigated by first-principles calculations and Monte Carlo simulation. With 3.125% doping, Mn 3d orbitals exhibit significant spin splitting and hybridize strongly with Cu 4d and Cl (Br) 3p orbitals, resulting in a net magnetic moment of 4.619 and 4.580 mu(B) in CuCl and CuBr, respectively. The formation energy is 255.5 MeV for CuCl and 400.5 MeV for CuBr, indicating that Mn doping can be easily realized in the experiment. With 6.25% doping, ferromagnetic ground state is favored in most of the doping configurations. The Curie temperature is estimated at 420 K for CuCl and 275 K for CuBr by Monte Carlo simulation. Thus Mn-doped CuCl and CuBr are promising candidates for room-temperature ferromagnetic materials. The ferromagnetism of the two systems can be explained by a hole-mediated double exchange mechanism. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698357]