Synthesis of a new copper oxide "In0.3Cu 0.7Ba2LaCu2Oy" and characterization of its physical properties

Masaaki Fujihara, Fumiaki Sato, Tatsuaki Nakano, Shiro Kambe, Osamu Ishii, Masahiko Nishijima

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    Though we previously reported a copper oxide, InBa2CuO y with an a-axis length of 4.18Å, its electric property was insulating. Based on the assumption that the insulating property comes from the existence of the oxygen vacancy correlated with the extremely long a-axis length, shortening the a-axis length below 4.0Å was tried to diminish the oxygen vacancy. The compound that we expected is represented by In xCu1-xBa2LnCu2Oy (In1212). To prepare the InxCu1-xBa2LnCu 2Oy, various kind of lanthanoides revealing that the smallest amount of impurity phases was formed when Ln = La. With changing the In content, x in InxCu1-xBaLa2Cu 2Oy from 0.2 to 1.0, the least impurity was prepared when x was 0.3. The XRD pattern of In0.3Cu0.7Ba 2LaCu2Oy was refined by the Rietveld analysis, suggesting that the structure is tetragonal with a-axis length of3.91±0.03 Ǻ and a c-axis length of 11.81±0.09 Ǻ, and is similar in structure to LaBa2Cu 3Oy except the partial substitution of In for Cu(2) Its resistivity was semiconducting. After annealing in O2, the resistivity was drastically decreased, but superconductivity was not observed above the temperature of 10K. According to the Hall effect measurement, the hole density of the oxygen-annealed sample was 7.9 × 1019 cm -3 at room temperature. While the ratio of itinerant holes v/p in the YBa2Cu3O6.76 superconductor was as large as 100-200%, the ratio for In0.3Cu0.7Ba2LaCu 2Oy was 0.001% to 10%, suggesting that the majority of holes are maybe localized in the In,Cu(2) plane.

    Original languageEnglish
    Title of host publicationElectroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology
    Number of pages10
    Publication statusPublished - 2006 Dec 1
    Event6th Pacific Rim Conference on Ceramic and Glass Technology - Maui, Hawaii, United States
    Duration: 2005 Sep 112005 Sep 16

    Publication series

    NameCeramic Transactions
    ISSN (Print)1042-1122


    Other6th Pacific Rim Conference on Ceramic and Glass Technology
    Country/TerritoryUnited States
    CityMaui, Hawaii

    ASJC Scopus subject areas

    • Ceramics and Composites
    • Materials Chemistry


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