Effects of Ca substitution on the electronic structure of Nd{sub 2{minus}x{minus}y}Ce{sub x}Ca{sub y}CuO{sub 4{minus}{delta}}

Journal Article · Mon Sep 01 00:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.5673· OSTI ID:538591

Chen, X H; Li, T F; Yu, M; Cao, L Z ^[1]; Li, Q; Xu, P S; Zhang, X Y ^[2]

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1. Structural Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, Peoples Republic of (China)
2. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, Peoples Republic of (China)

The effects of Ca substitution on the core levels and valence electronic states of Nd{sub 2{minus}x{minus}y}Ce{sub x}Ca{sub y}CuO{sub 4{minus}{delta}} have been studied using x-ray-photoelectron spectroscopy. It is found that the fraction of monovalent Cu derived from the Cu-2p spectra apparently increases with increasing Ca concentration. Ca doping leads to an enhancement in the density of states at the Fermi level for superconducting Nd{sub 1.85{minus}y}Ce{sub 0.15}Ca{sub y}CuO{sub 4{minus}{delta}}. This could arise from Ca doping making it easier to lose oxygen from the samples and lead to an increase in electron carriers. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 538591
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM OXIDES
CERIUM OXIDES
COPPER OXIDES
ELECTRONIC STRUCTURE
FERMI LEVEL
HIGH-TC SUPERCONDUCTORS
NEODYMIUM OXIDES
PHOTOELECTRON SPECTROSCOPY
STOICHIOMETRY
VALENCE