Superconducting fluctuations in Bi[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub [ital x]] thin films: Paraconductivity, excess Hall effect, and magnetoconductivity

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.9180· OSTI ID:6449471

Lang, W; Heine, G ^[1]; Kula, W; Sobolewski, R ^[2]

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1. Ludwig Boltzmann Institut fuer Festkoerperphysik, Kopernikusgasse 15, A-1060 Wien (Austria) Institut fuer Festkoerperphysik, Universitaet Wien (Austria)
2. Department of Electrical Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14627 (United States)

A detailed study of normal-state magnetotransport properties in (Bi,Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub [ital x]] thin films with a zero-resistance critical temperature [ital T][sub [ital c]0]=105 K prepared by dc-magnetron sputtering on MgO substrates is reported. Measurements of the electrical resistivity, the magnetoresistance, and the Hall effect are analyzed with regard to contributions of the superconducting order-parameter thermodynamic fluctuations, using theories for two-dimensional, layered superconductors. We have obtained a consistent set of parameters, i.e., the in-plane coherence length [xi][sub [ital a][ital b]](0)=1.6 nm, the out-of-plane coherence length [xi][sub [ital c]](0)=0.14 nm, and the electron-hole asymmetry parameter [beta]=[minus]0.38. At temperatures below 118 K, we observe a remarkable enhancement (above theoretical predictions) of both the excess Hall effect and magnetoconductivity, whereas no such effect is detected for the zero-field paraconductivity. The above anomalies are attributed to a nonuniform critical temperature distribution inside our samples and can be well explained assuming a Gaussian distribution of [ital T][sub [ital c]]'s with a standard deviation [delta][ital T][sub [ital c]]=2.3 K. The excess Hall effect caused by superconducting fluctuations is negative in the entire accessible temperature range, which indicates, together with the paraconductivity and magnetoconductivity results that the indirect (Maki-Thompson) fluctuation process for (Bi,Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub [ital x]] is vanishingly small at temperatures from [ital T][sub [ital c]] to 130 K.

• OSTI ID: 6449471
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 51:14; 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
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL TEMPERATURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FILMS
FLUCTUATIONS
HALL EFFECT
HIGH-TC SUPERCONDUCTORS
LEAD COMPOUNDS
LEAD OXIDES
MAGNETORESISTANCE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VARIATIONS