Charge Disproportionation and Complex Magnetism in a PbMnO3Perovskite Synthesized under High Pressure
Because of the possible crossover of Pb and 3d transition-metal (TM) redox levels, a charge transfer between Pb and TM leads to a continuous evolution from Pb2+Ti4+O3 to Pb4+Ni2+O3 in the perovskite family of PbTMO3. However, very little information is known about PbMnO3 in the PbTMO3 series. The perovskite PbMnO3 is the most difficult one to synthesize. We report a careful study of PbMnO3 synthesized under 15 GPa by a structural refinement and high precision X-ray absorption spectroscopy (XAS) as well as a variety of measurements of physical properties. We can rationalize the physical properties of PbMnO3 based on a local bonding model and the valence states of Pb and Mn from XAS. Moreover, the complete study of PbMnO3 allows us to construct a more consistent picture of the valence evolution and the charge disproportionation for the entire family of PbTMO3 perovskites.