Charge disproportionation and the pressure-induced insulator?metal transition in cubic perovskite PbCrO3

• Autores: Cheng, Jinguang; Kweon, K. E.; Larregola, Sebastian Alberto; Ding, Yang; Shirako, Y.; Marshall, L. G.; Li, Z. Y.; Li, X.; Dos Santos, António M.; Suchomel, M. R.; Matsubayashi, K.; Uwatoko, Y.; Hwang, G. S.; Goodenough, John B.; Zhou, J. S.
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: High Pressure; Perovskite; Insulator-Metal Transition; Charge Disproportionation
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The perovskite PbCrO3 is an antiferromagnetic insulator. However, the fundamental interactions leading to the insulating state in this single-valent perovskite are unclear. Moreover, the origin of the unprecedented volume drop observed at a modest pressure of P = 1.6 GPa remains an outstanding problem. We report a variety of in situ pressure measurements including electron transport properties, X-ray absorption spectrum, and crystal structure study by X-ray and neutron diffraction. These studies reveal key information leading to the elucidation of the physics behind the insulating state and the pressure-induced transition. We argue that a charge disproportionation 3Cr4+ → 2Cr3+ + Cr6+ in association with the 6s-p hybridization on the Pb2+ is responsible for the insulating ground state of PbCrO3 at ambient pressure and the charge disproportionation phase is suppressed under pressure to give rise to a metallic phase at high pressure. The model is well supported by density function theory plus the correlation energy U (DFT+U) calculations.
Fil: Cheng, Jinguang. University Of Texas At Austin; Estados Unidos. Chinese Academy Of Sciences; República de China. University of Tokyo. Institute for Solid State Physics; Japón
Fil: Kweon, K. E.. University Of Texas At Austin; Estados Unidos
Fil: Larregola, Sebastian Alberto. University Of Texas At Austin; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; Argentina
Fil: Ding, Yang. Argonne National Laboratory; Estados Unidos
Fil: Shirako, Y.. University Of Texas At Austin; Estados Unidos
Fil: Marshall, L. G.. University Of Texas At Austin; Estados Unidos. Northeastern University; Estados Unidos
Fil: Li, Z. Y.. University Of Texas At Austin; Estados Unidos
Fil: Li, X.. University Of Texas At Austin; Estados Unidos
Fil: Dos Santos, António M.. Oak Ridge National Laboratory. Quantum Condensed Matter Division; Estados Unidos
Fil: Suchomel, M. R.. Argonne National Laboratory; Estados Unidos
Fil: Matsubayashi, K.. University of Tokyo. Institute for Solid State Physics; Japón
Fil: Uwatoko, Y.. University of Tokyo. Institute for Solid State Physics; Japón
Fil: Hwang, G. S.. University Of Texas At Austin; Estados Unidos
Fil: Goodenough, John B.. University Of Texas At Austin; Estados Unidos
Fil: Zhou, J. S.. University Of Texas At Austin; Estados Unidos