Upper critical field of Ba[sub 1[minus][ital x]]K[sub [ital x]]BiO[sub 3] single crystals

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.3502· OSTI ID:5222511

Affronte, M; Marcus, J; Escribe-Filippini, C ^[1]; Sulpice, A ^[2]; Rakoto, H; Broto, J M; Ousset, J C; Askenazy, S ^[3]; Jansen, A G.M. ^[4]

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1. Laboratoire d'Etudes des Proprietes Electroniques des Solides, Centre National de la Recherche Scientifique, Boite Postale 166, 38042 Grenoble (France)
2. Centre de Recherches sur les Tres Basses Temperatures, Centre National de la Recherche Scientifique, Boite Postale 166, 38042 Grenoble (France)
3. Laboratoire de Physique des Solides et Service National des Champs Pulses, 31077 Toulouse (France)
4. High Magnetic Field Laboratory, Max-Planck-Institut fuer Festkoerforschung, Boite Postale 166, 38042 Grenoble (France)

We report an extensive study on the temperature ([ital T]) dependence of the upper critical field [ital H][sub [ital c]2] on Ba[sub 1[minus][ital x]]K[sub [ital x]]BiO[sub 3] single crystals. The [ital H][sub [ital c]2]([ital T]) curve shows a reproducible upward curvature at [similar to]22 K. This can be due to the presence of two superconducting phases, one with [ital T][sub [ital c]][similar to]30 K and low [ital H][sub [ital c]2] ([[ital dH][sub [ital c]2]/[ital dT]][sub [ital T][ital c]][similar to]0.5 T/K) and another one with [ital T][sub [ital c]][similar to] 25 K and higher [ital H][sub [ital c]2] ([[ital dH][sub [ital c]2]/[ital dT]][sub [ital T][ital c]][similar to]1.1 T/K). However, we find that [ital H][sub [ital c]2] may rise up to 32 T at 1.8 K. It turns out that the reduced critical field [ital h][sub [ital c]2]=[ital H][sub [ital c]2]/[[ital T][sub [ital c]]([ital dH][sub [ital c]2]/[ital dT])[sub [ital T][ital c]]] is [ge]1 at low temperatures for both the 30- and 25-K phases, i.e., much higher than what is expected for a conventional superconductor. We compare the low-temperature [ital h][sub [ital c]2] data with calculations recently performed by Marsiglio and Carbotte in the framework of an extended Werthamer-Helfand-Hohenberg theory.

• OSTI ID: 5222511
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:5; 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
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
CRITICAL FIELD
HIGH-TC SUPERCONDUCTORS
MAGNETIC FIELDS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM OXIDES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE