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Title: Unusual Mott transition in multiferroic PbCrO 3

The Mott insulator in correlated electron systems arises from classical Coulomb repulsion between carriers to provide a powerful force for electron localization. When turning such an insulator into a metal, the so-called Mott transition, is commonly achieved by "bandwidth" control or "band filling." However, both mechanisms deviate from the original concept of Mott, which attributes such a transition to the screening of Coulomb potential and associated lattice contraction. We report a pressure-induced isostructural Mott transition in cubic perovskite PbCrO3. At the transition pressure of similar to 3 GPa, PbCrO3 exhibits significant collapse in both lattice volume and Coulomb potential. Concurrent with the collapse, it transforms from a hybrid multiferroic insulator to a metal. For the first time to our knowledge, these findings validate the scenario conceived by Mott. Close to the Mott criticality at similar to 300 K, fluctuations of the lattice and charge give rise to elastic anomalies and Laudau critical behaviors resembling the classic liquid-gas transition. Moreover, the anomalously large lattice volume and Coulomb potential in the low-pressure insulating phase are largely associated with the ferroelectric distortion, which is substantially suppressed at high pressures, leading to the first-order phase transition without symmetry breaking.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [9] ;  [10] ;  [6] ;  [6] ;  [11]
  1. Sichuan Univ., Chengdu (China); Univ. of Nevada, Las Vegas, NV (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of Nevada, Las Vegas, NV (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chinese Academy of Sciences (CAS), Beijing (China)
  3. Univ. of Nevada, Las Vegas, NV (United States)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chinese Academy of Sciences (CAS), Beijing (China)
  5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  6. Sichuan Univ., Chengdu (China)
  7. Univ. of Nevada, Las Vegas, NV (United States); Carnegie Inst. of Washington, Argonne, IL (United States)
  8. US Synthetic Corporation, Orem, UT (United States)
  9. Univ. of Florida, Gainesville, FL (United States)
  10. Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)
  11. Univ. of Nevada, Las Vegas, NV (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
OSTI Identifier:
1261490
Grant/Contract Number:
AC05-00OR22725; FC52-06NA27684; 2011CB808205; NA0001974; FG02-99ER45775; AC02-06CH11357; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 112; Journal Issue: 50; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY Mott transition; multiferroics; PbCrO3; Mott criticality; isostructural transition; HIGH-PRESSURE; ELECTRONIC-STRUCTURE; VOLUME COLLAPSE; METAL OXIDES; PEROVSKITE; ANTIFERROMAGNETISM; PHOTOEMISSION