Ferromagnetism and antiferromagnetism coexistence in SrRu1−xMnxO3: Density functional calculation

We have calculated the electronic structure of SrRu1−xMnxO3 using the full potential linearized augmented plane wave method by LSDA and LSDA+U. The antiparallel alignment between the Mn and Ru ions are consistent with the competition between ferromagnetism and antiferromagnetism in the low Mn-doped polycrystalline samples. This is in contrast to the appearance of quantum critical point and FM and AFM transitions in the single crystal measurement. Our results show that the discrepancy between different experimental phase diagrams is related to the conditions of sample preparation and also the difference between the degree of magnetic interactions between the Mn and Ru moments. The DOS and the calculated Mn magnetic moment is similar to the magnetic moment of a purely ionic compound with d3 configuration. The AFM state has band gap of 1.2 eV at the Fermi energy predicting an insulating behavior.