Stability of the Pb divalent state in insulating and metallic PbCrO3

Article

关键词: HIGH-PRESSURE SYNTHESIS;    TRANSITION;    PEROVSKITE;    CRYSTAL;    3D;   

DOI  :  10.1103/PhysRevB.107.024107

来源: SCIE

【 摘 要 】

We have investigated the local electronic structure of PbCrO3 by conducting x-ray absorption spectroscopy at the lead L3 and chromium L2,3 edges. We found that lead is divalent and chromium is charge-disproportionated into trivalent and hexavalent states at ambient pressures, explaining their insulating behavior. The high-resolution partial fluorescence yield of lead L3 spectra as a function of pressure revealed that the divalent state of lead ions remains unchanged at high pressures, when PbCrO3 changes into metal and its volume collapses by more than 10%. We infer that the insulator-to-metal transition does not involve a Pb-Cr charge transfer, but is associated with the conversion of Cr3+/Cr6+ charge-disproportionated states into a Cr4+ valence state.

【 授权许可】

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