Magnetic properties of crystalline and amorphous phase-change materials doped with 3d impurities

First-principles study of the structural and magnetic properties of cubic and amorphous phase-change materials doped with 3d impurities. We find that Co- and Ni-doped Ge₂Sb₂Te₅ is non-magnetic, whereas Cr- and Mn-doped Ge₂Sb₂Te₅ is magnetic and exhibits a significant magnetic contrast between the two phases in the ferromagnetic configuration. These results are explained in terms of differences in local structure and hybridization of the impurity d-orbitals with the host states.