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

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 probl...

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Detalhes bibliográficos
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.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/5882
Acesso em linha:http://hdl.handle.net/11336/5882
Access Level:acceso abierto
Palavra-chave:High Pressure
Perovskite
Insulator-Metal Transition
Charge Disproportionation
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo: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.

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