Abstract
We have investigated the structure and electronic properties of ferrimagnetic double perovskites, The phase is cubic and metallic, while the phase is monoclinic and nonmetallic. Mössbauer spectroscopy shows that iron is present mainly in the high spin state in the Ca compound, while it occurs in an intermediate state between high spin and in the Ba compound. It is argued that a direct interaction is the main cause for the metallic character of the Ba compound; the smaller size of Ca and the monoclinic distortion (which lifts the degeneracy of states) seem to disrupt the Re-Re interaction in the case of the Ca compound, making it nonmetallic for the same electron count.
- Received 18 April 2000
DOI:https://doi.org/10.1103/PhysRevB.62.9538
©2000 American Physical Society