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 00:00:00 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), Vol. 102:2; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERIUM OXIDES
ELECTRIC CONDUCTIVITY
COPPER OXIDES
DYSPROSIUM OXIDES
EUROPIUM OXIDES
GADOLINIUM OXIDES
HOLMIUM OXIDES
LANTHANUM OXIDES
LEAD OXIDES
NEODYMIUM OXIDES
PRASEODYMIUM OXIDES
SAMARIUM OXIDES
TERBIUM OXIDES
YTTRIUM OXIDES
CATIONS
CHEMICAL PREPARATION
CRYSTAL DOPING
CRYSTALS
ELECTRICAL INSULATORS
STOICHIOMETRY
SUPERCONDUCTORS
VACANCIES
CERIUM COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
COPPER COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DYSPROSIUM COMPOUNDS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
EQUIPMENT
EUROPIUM COMPOUNDS
GADOLINIUM COMPOUNDS
HOLMIUM COMPOUNDS
IONS
LANTHANUM COMPOUNDS
LEAD COMPOUNDS
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POINT DEFECTS
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SYNTHESIS
TERBIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
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