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Society Photoemission and Photoabsorption Study of YNi2−xCoxB2C Superconductors

Published online by Cambridge University Press:  21 March 2011

L.-S. Hsu
Affiliation:
Department of Physics, National Chang-Hua University of Education, Chang-Hua 50058, Taiwan, ROC
G. Y. Guo
Affiliation:
Department of Physics, National Taiwan University, Taipei 107, Taiwan, ROC Synchrotron Radiation Research Center, Hsinchu 300, Taiwan, ROC
C.-J. Chen
Affiliation:
Department of Physics, National Chang-Hua University of Education, Chang-Hua 50058, Taiwan, ROC
M.-D. Lan
Affiliation:
Department of Physics, National Chung Hsing University, Taichung 402, Taiwan, ROC
J.-F. Lee
Affiliation:
Synchrotron Radiation Research Center, Hsinchu 300, Taiwan, ROC
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Abstract

The electronic structures of five polycrystalline YNi2−xCoxB2C (x=0, 0.05, 0.1, 0.15, and 0.2) borocarbide superconductors were studied by photoemission and photoabsorption spectroscopies and theoretical calculations. The valence-band (VB) photoemission spectrum is compared with the theoretical total and partial density-of-states (DOS) curves. The VB satellite is peaked at a binding energy (EB) of 6 eV. The Ni K-edge x-ray absorption near edge spectra (XANES) are compared with the calculated XANES spectra for these intermetallic compounds. Extended x-ray absorption fine structure (EXAFS) spectra at the Ni and Co K edges are analyzed to yield the structural parameters. The decrease of the superconducting transition temperatures (Tc) with addition of Co dopant in these compounds is due to a decrease of the total DOS at the Fermi level (EF).

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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