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Meyers D, Mukherjee S, Cheng JG, Middey S, Zhou JS, Goodenough JB, Gray BA, Freeland JW, Saha-Dasgupta T, Chakhalian J. Zhang-Rice physics and anomalous copper states in A-site ordered perovskites. Sci Rep 2013; 3:1834. [PMID: 23666066 PMCID: PMC3652288 DOI: 10.1038/srep01834] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/24/2013] [Indexed: 01/08/2023] Open
Abstract
In low dimensional cuprates several interesting phenomena, including high Tc superconductivity, are deeply connected to electron correlations on Cu and the presence of the Zhang-Rice (ZR) singlet state. Here, we report on direct spectroscopic observation of the ZR state responsible for the low-energy physical properties in two isostructural A-site ordered cuprate perovskites, CaCu(3)Co(4)O(12) and CaCu(3)Cr(4)O(12) as revealed by resonant soft x-ray absorption spectroscopy on the Cu L(3,2)- and O K-edges. These measurements reveal the signature of Cu in the high-energy 3+ (3d(8)), the typical 2+ (3d(9)), as well as features of the ZR singlet state (i.e., 3d(9)L, L denotes an oxygen hole). First principles GGA + U calculations affirm that the B-site cation controls the degree of Cu-O hybridization and, thus, the Cu valency. These findings introduce another avenue for the study and manipulation of cuprates, bypassing the complexities inherent to conventional chemical doping (i.e. disorder) that hinder the relevant physics.
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Affiliation(s)
- D. Meyers
- Department of Physics, University of Arkansas, Fayetteville, AR 72701
| | - Swarnakamal Mukherjee
- Department of Condensed Matter Physics and Materials Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700098, India
| | - J.-G. Cheng
- Texas Materials Institute, ETC 9.102, University of Texas at Austin, Austin, Texas 78712
- Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba Japan 277-8581
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - S. Middey
- Department of Physics, University of Arkansas, Fayetteville, AR 72701
| | - J.-S. Zhou
- Texas Materials Institute, ETC 9.102, University of Texas at Austin, Austin, Texas 78712
| | - J. B. Goodenough
- Texas Materials Institute, ETC 9.102, University of Texas at Austin, Austin, Texas 78712
| | - B. A. Gray
- Department of Physics, University of Arkansas, Fayetteville, AR 72701
| | - J. W. Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T. Saha-Dasgupta
- Department of Condensed Matter Physics and Materials Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700098, India
| | - J. Chakhalian
- Department of Physics, University of Arkansas, Fayetteville, AR 72701
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637 371, Singapore
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