1. Local Electronic Structure of Doping Atoms in MA[sub 2]Ca[sub n-1]Cu[sub n]O[sub 2n+3] High-T[sub C] Superconductors with [M-12(n-1)n] Type Structures.
- Author
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Kurmaev, E. Z., Moewes, A., Zhigadlo, N. D., Takayama-Muromachi, E., Nekrasov, I. A., Bureev, O. A., Woods, G. T., Callcott, T. A., Yarmoshenko, Yu. M., Shamin, S. N., Ederer, D. L., and Yanagihara, M.
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ATOMS ,SUPERCONDUCTORS ,ELECTRONIC structure - Abstract
Results of X-ray fluorescence measurements of MA[sub 2]Ca[sub n-1]Cu[sub n]O[sub 2n+3] compounds with [M-12(n 1)n] type structures, (C[sub 0.8]N[sub 0.2]Sr[sub 2]CuO[sub 5.3], [Cu[sub 0.25](C,N)[sub 0.75]]Sr[sub 2]CaCu[sub 2]O[sub y], Cu[sub 0.5]V[sub 0.5]Sr[sub 2]CaCu[sub 2]O[sub 7.5], Cu[sub 0.5]V[sub 0.5]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 9.4], Cu[sub 0.5]V[sub 0.5]Sr[sub 2](Ca[sub 3.6]Sr[sub 0.4])Cu[sub 5]O[sub 13.5] and Cu[sub 0.5]V[sub 0.5]Sr[sub 2](Ca[sub 4.7]Sr[sub 0.3])Cu[sub 6]O[sub 15.3]), are presented. The experiments show that C-atoms form a distorted CO[sub 3] oxyacid group with a partial substitution of copper and nitrogen atoms in the M-sites. We conclude that the CO[sub 3, sup 2-] group in (C,N) Sr[sub 2]Ca[sub n-1]Cu[sub n]O[sub y] and (Cu,C,N) Sr[sub 2]Ca[sub n-1]Cu[sub n]O[sub y] is substituted by the NO[sub 2, sup -] which induces the creation of the hole carriers in these compounds. We have found that V-atoms in the given compounds form (VO[sub 4])[sup 3-] tetrahedrons and have a pentavalent state. [ABSTRACT FROM AUTHOR]
- Published
- 2002
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