Semiconducting (half-metallic) ferromagnetism in Mn(Fe) substituted Pt and Pd nitrides

Using first-principles calculations as based on density-functional theory, we propose a class of so far unexplored diluted ferromagnetic semiconductors and half metals. Here, we study the electronic properties of recently synthesized 4d and 5d transition-metal dinitrides. In particular, we address Mn and Fe substitution in PtN2 and PdN2. Structural relaxation shows that the resulting ordered compounds, Pt0.75(Mn,Fe)0.25N2 and Pd0.75(Mn,Fe)0.25N2, maintain the cubic crystal symmetry of the parent compounds. On substitution, all compounds exhibit long-range ferromagnetic order. While both Pt0.75Mn0.25N2 and Pd0.75Mn0.25N2 are semiconducting, Fe substitution causes half-metallic behavior for both parent materials