Superconducting and nonsuperconducting Ca-free single crystals of Pb[sub 2]Sr[sub 2]RCu[sub 3]O[sub 8] (R = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Y): Effect of cation vacancies and the metal/insulator transition

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1006/jssc.1993.1061· OSTI ID:6517739

Xue, J S; Reedyk, M; Greedan, J E; Timusk, T ^[1]

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1. McMaster Univ., Hamilton, Ontario (Canada)

Ca-free single crystal and polycrystalline samples of Pb[sub 2]Sr[sub 2]RCu[sub 3]O[sub 8] have been prepared by a PbO/NaCl flux growth method and a fast solid state reaction, respectively. The electronic character of the single crystals of this series can be roughly categorized into three groups: insulating (no carrier doping in the CuO[sub 2] planes) for R = La, Ce, Pr, and Nd, semiconducting for R = Sm, Eu, Gd, and Tb, and poorly metallic for R = Dy, Ho, and Y. Crystals with R = Eu to Ho are found to be superconducting with the exception of Tb. The metallic character in these crystals is likely promoted by a cation vacancy at the rare-earth sites which has been established by crystal structural and chemical analyses. The anomalous behavior of the Tb crystals may originate from a lower dopant level as inferred from the structure determination or possibly from the presence of Tb[sup 4+]. The fact that metallic behavior is observed in nonstoichiometric polycrystalline samples and not in stoichiometric ones seems consistent with the cation vacancy carrier doping mechanism. 22 refs., 7 figs., 4 tabs.

• OSTI ID: 6517739
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 102:2; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
360207 -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
CATIONS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL PREPARATION
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL DEFECTS
CRYSTAL DOPING
CRYSTAL STRUCTURE
CRYSTALS
DYSPROSIUM COMPOUNDS
DYSPROSIUM OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATORS
ELECTRICAL PROPERTIES
EQUIPMENT
EUROPIUM COMPOUNDS
EUROPIUM OXIDES
GADOLINIUM COMPOUNDS
GADOLINIUM OXIDES
HOLMIUM COMPOUNDS
HOLMIUM OXIDES
IONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LEAD COMPOUNDS
LEAD OXIDES
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POINT DEFECTS
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
STOICHIOMETRY
SUPERCONDUCTORS
SYNTHESIS
TERBIUM COMPOUNDS
TERBIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
VACANCIES
YTTRIUM COMPOUNDS
YTTRIUM OXIDES