Charge disproportionation and the pressure-induced insulator–metal transition in cubic perovskite PbCrO ₃

Journal Article · Mon Jan 26 00:00:00 EST 2015 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.1424431112· OSTI ID:1235506

Cheng, Jinguang ^[1]; Kweon, K. E. ^[2]; Larregola, S. A. ^[3]; Ding, Yang ^[4]; Shirako, Y. ^[3]; Marshall, L. G. ^[5]; Li, Z. -Y. ^[3]; Li, X. ^[3]; dos Santos, António M. ^[6]; Suchomel, M. R. ^[4]; Matsubayashi, K. ^[7]; Uwatoko, Y. ^[7]; Hwang, G. S. ^[2]; Goodenough, John B. ^[3]; Zhou, J. -S. ^[3]

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1. Materials Science and Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712,, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China,, Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan,
2. Chemical Engineering and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712,
3. Materials Science and Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712,
4. Advanced Photo Source, Argonne National Laboratory, Argonne, IL 60439,
5. Materials Science and Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712,, Department of Chemical Engineering, Northeastern University, Boston, MA 02115, and
6. Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
7. Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan,

The perovskite PbCrO₃ is an antiferromagnetic insulator. But, 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. Our report shows 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. Furthermore, 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.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-06CH11357; AC05-00OR22725
• OSTI ID: 1235506
• Alternate ID(s): OSTI ID: 1334440
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 112 Journal Issue: 6; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of Sciences
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
high pressure
perovskite
insulator-metal transition
charge disproportionation
LARGE-VOLUME
MICROSTRUCTURE
SPECTROSCOPY
CHROMIUM
CRYSTAL