Evidence for the band ferromagnetism in SrRuO3 from neutron diffraction

The precise data on the crystal and magnetic structures of SrRuO3 were obtained by neutron diffraction. The ferromagnetically ordered Ru moment amounts to μRu=1.63±0.06 μB at T=10K. This value agrees well with the results of recent electronic structure calculations, which predicted the possibility of band ferromagnetism in SrRuO3 with the reduced ordered moment. The crystal structure of SrRuO3 remains practically invariable in the temperature range of 1.5–290 K. We have also found that the “Invar effect” in SrRuO3 (zero thermal expansion coefficient) is stipulated entirely by freezing of the mutual rotations/tilts of the oxygen octahedra below the phase transition into the ferromagnetic phase.