Reversible and irreversible magnetization of the Chevrel-phase superconductor PbMo{sub 6}S{sub 8}

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.12931· OSTI ID:165774

Zheng, D N; Ramsbottom, H D; Hampshire, D P ^[1]

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1. Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom)

Magnetic measurements have been carried out on the hot-isostatically-pressed Chevrel-phase superconductor PbMo{sub 6}S{sub 8} at temperatures from 4.2 K to {ital T}{sub {ital c}} and for magnetic fields up to 12 T. The results show that for the PbMo{sub 6}S{sub 8} compound there is a wide magnetically reversible region, between the irreversibility field {ital B}{sub irr} and the upper critical field {ital B}{sub {ital c}2}, on the isothermal magnetic hysteresis curves. The {ital B}{sub irr}({ital T}) line, i.e., the irreversibility line, was found to obey a power-law expression: {ital B}{sub irr}={ital B}{sup *}(1{minus}{ital T}/{ital T}{sub {ital c}}){sup {alpha}} with {alpha}{approx}1.5. Magnetic relaxation measurements revealed that the flux-creep effect in the material studied is substantial and is greater than those observed in conventional metallic alloys, but smaller than in high-temperature superconductors. The existence of the irreversibility line and pronounced flux-creep effect in PbMo{sub 6}S{sub 8} is attributed to the short coherence length of the material. From the reversible magnetization data, the values of the penetration depth, the coherence length, and the critical fields are obtained together with the Ginzburg-Landau parameter {kappa}. At 4.2 K, the critical current density {ital J}{sub {ital c}} is 10{sup 9} A m{sup {minus}2} at zero field, and decreases to 2{times}10{sup 8} A m{sup {minus}2} at 10 T. Pinning force curves measured at different temperatures obey a Kramer-scaling law of the form: {ital F}{sub {ital p}}(={ital J}{sub {ital c}}{times}{ital B}){proportional_to}{ital b}{sup 1/2}(1{minus}{ital b}){sup 2}, which indicates that the {ital J}{sub {ital c}} is limited by one predominant flux-pinning mechanism.

• OSTI ID: 165774
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 52; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COHERENCE LENGTH
CRITICAL FIELD
GINZBURG-LANDAU THEORY
LEAD SULFIDES
MAGNETIC FLUX
MAGNETIZATION
MOLYBDENUM SULFIDES
PENETRATION DEPTH
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE