Double resistive superconducting transition in Sm[sub 2[minus][ital x]]Ce[sub [ital x]]CuO[sub 4[minus][ital y]]

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.47.433· OSTI ID:7118771

Early, E A; Almasan, C C; Jardim, R F; Maple, M B ^[1]

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1. Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)

We report a systematic study of the double resistive superconducting transition in carefully prepared polycrystalline samples of the electron-doped superconducting series Sm[sub 2[minus][ital x]]Ce[sub [ital x]]CuO[sub 4[minus][ital y]] for 0.12[le][ital x][le]0.20. From high-resolution x-ray-diffraction measurements, the solubility limit of Ce in this series is slightly greater than 0.16. An intrinsic double resistive transition present in all superconducting compounds is attributed to the granularity of these polycrystalline samples. There is a partial transition when the grains become superconducting at a temperature [ital T][sub [ital c]1], and coupling between grains at a lower temperature [ital T][sub [ital c]2] apparently completes the transition. Only the transition associated with coupling between grains is observed in magnetic-susceptibility measurements due to inhomogeneous grains and large penetration depths. From compositional dependences of resistive and magnetic measurements, the superconducting volume fraction increases linearly with increasing dopant concentration up to the solubility limit, while the best coupling between grains is at a dopant concentration of 0.15. Thus, there is a subtle relationship between doping and coupling in this series. Also, arguments for a true thermodynamic phase transition at [ital T][sub [ital c]2] are given.

• DOE Contract Number: FG03-86ER45230
• OSTI ID: 7118771
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 47:1; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
HIGH-TC SUPERCONDUCTORS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYCRYSTALS
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE