Realizing ferromagnetic semiconductors in SrRu_1−xZr_xO₃ alloys.

Using first principle calculations, we study the structural, electric and magnetic properties of SrRu_1−xZr_xO₃ (0 ≤ x ≤ 1). The spin-polarization calculations present that SrRu_1−xZr_xO₃ is a ferromagnetic metal at x = 0, a ferromagnetic semiconductor at x = 0.125, 0.25, an antiferromagnetic semiconductor at x = 0.5 and a nonmagnetic insulator at x = 1, which is in agreement with available experiments. As increasing Zr contents, the lattice parameters and band gaps of SrRu_1−xZr_xO₃ increase while the energy difference between antiferromagnetic and ferromagnetic states decreases. Through Ru-O and Zr-O bonds, hybridization between Ru 4d and Zr 4d states near the Fermi level becomes strong. As a result, Ru 4d states split and then metal-insulator transition occurs at x = 0.125 due to Zr. Ferromagnetic semiconductors are first predicted in SrRu_1−xZr_xO₃ alloys, which may have potential applications in spintronic devices. [ABSTRACT FROM AUTHOR]