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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