Influence of calcium on transport properties, band spectrum and superconductivity of YBa{sub 2}Cu{sub 3}O{sub y} and YBa{sub 1.5}La{sub 0.5}Cu{sub 3}O{sub y}{sup {center_dot}}
- State Technical Univ., St. Petersburg (Russian Federation)
- Institute of Silicate Chemistry, St. Petersburg (Russian Federation)
The comparative investigation of transport phenomena in Y{sub 1-x}Ca{sub x}Ba{sub 2}Cu{sub 3}O{sub y} (0<0.25, 6.96>y>6.87 and 6.73<6.53), Y{sub 1-x}Ca{sub x}Ba{sub 1.5}La{sub 0.5}Cu{sub 3}O{sub y} (0<0.5, 7.12>y>6.96) and YBa{sub 2-x}La{sub x}Cu{sub 3}O{sub y} (0<0.5, 6.95<7.21) systems have been carried out. The temperature dependencies of resistivity and thermopower have been measured. It was found that the S(T) dependencies take some additional features with Ca content increase. The results obtained have been analyzed on the basis of the phenomenological theory of electron transport in the case of the narrow conductive band. The main parameters of the band spectrum (the band filling with electrons degree and the total effective band width) have been determined. The dependencies of these ones from contents of substituting elements are discussed. Analyzing the results obtained simultaneously with the tendencies in oxygen content and critical temperature change we have confirmed the conclusion that the oxygen sublattice disordering has a determinant effect on band structure parameters and superconductive properties of YBa{sub 2}Cu{sub 3}O{sub y}{sup {center_dot}}. The results obtained suggest that Ca gives rise to some peculiarities in band spectrum of this compound.
- Research Organization:
- National Aeronautics and Space Administration (NASA), Washington, DC (United States); National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center
- OSTI ID:
- 121643
- Report Number(s):
- CONF-940627-Vol.2; ON: TI95017155; TRN: 99:003582
- Resource Relation:
- Conference: 4. international conference and exhibition of the World Congress on Superconductivity, Orlando, FL (United States), 27 Jun - 1 Jul 1994; Other Information: PBD: 1994; Related Information: Is Part Of Proceedings of the fourth international conference and exhibition: World Congress on superconductivity. Volume 2; Krishen, K.; Burnham, C. [eds.] [National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center]; PB: 400 p.
- Country of Publication:
- United States
- Language:
- English
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