Suppression of superconductivity in PrBa sub 2 Cu sub 3 O sub 7 : 4 f and conduction-band hybridization effect

Journal Article · Sun Apr 01 00:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.6372· OSTI ID:6947498

Guo, G Y; Temmerman, W M ^[1]

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1. United Kingdom Science, Daresbury Laboratory, Warrington WA4 4AD, (United Kingdom) Engineering Research Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom (GB)

In order to understand the suppression of superconductivity in Y{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7} (0.6{le}{ital x}{le}1.0) and also the electronic properties of the high-{ital T}{sub {ital c}} superconductors {ital R}Ba{sub 2}Cu{sub 3}O{sub 7} ({ital R} denoting the rare earths except Ce, Pr, Pm, and Tb), we have performed self-consistent, spin-polarized electronic structure and all-electron total-energy calculations for three representative materials: {ital R}Ba{sub 2}Cu{sub 3}O{sub 7} ({ital R}=Y, Pr, and Gd). The salient results are that the band structures of the {ital R}Ba{sub 2}Cu{sub 3}O{sub 7} compounds are nearly the same as that of YBa{sub 2}Cu{sub 3}O{sub 7} when {ital R} ions assume trivalency, and extra electrons donated by the hypothetical tetravalent Pr ions would mainly fill the conduction bands in a rigid-band manner, thereby substantially reducing the important hole'' account. However, the tetravalent Pr compound is shown to be energetically less favorable than the trivalent Pr compound; finally, large spin splittings (up to 75 meV) are found in the conduction bands around the Fermi level in PrBa{sub 2}Cu{sub 3}O{sub 7} when the 4{ital f} and conduction-band hybridization effects are taken into account. In contrast, such spin splittings are ten to five times smaller in GdBa{sub 2}Cu{sub 3}O{sub 7}. This result corroborates that the magnetic pair breaking is responsible for the suppression of superconductivity in the Pr compound.

• OSTI ID: 6947498
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 41:10; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
ELECTRONIC STRUCTURE
COPPER OXIDES
PRASEODYMIUM OXIDES
YTTRIUM OXIDES
BAND THEORY
CRYSTAL STRUCTURE
HYBRIDIZATION
SUPERCONDUCTIVITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity