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.

The antiparallel alignment between the Mn and Ru ions are consistent with the competition between ferromagnetism and antiferromagnetism with the formation of a spin glass phase. We have calculated the electronic structure of SrRu1−xMnxO3 using the full potential linearized augmented plane wave method by LSDA and LSDA+U in the range of both low and high Mn-doping for parallel and antiparallel alignments of Ru and Mn moments. In the low Mn-doped polycrystalline samples with tetragonal structure, the AFM hybridization between Mn and the Ru host lattice strongly favors alignment of the Ru moments, and provides an explanation for retaining of high Curie temperature of SrRuO3 with Mn substitution.Figure optionsDownload as PowerPoint slideResearch highlights
► For the low Mn-doping the AFM coupling between Mn and Ru becomes stable.
► Results are consistent with the QCP between FM and AFM transitions in single crystals.
► In high Mn-doping, electron correlation is important in predicting the insulating behavior.