Origin of the linear'' term in the specific heat of YBa sub 2 Cu sub 3 O sub 7

Conference · Sat Jul 01 04:00:00 EDT 1989

OSTI ID:5555812

Phillips, N. E.; Fisher, R. A.; Gordon, J. E.; Kim, S.

We report measurements of the specific heat, C, of a number of samples of YBCO, and interpret the results as showing the existence of localized magnetic moments on the YBCO lattice that suppress the transition to the superconducting state. Both the extent of the transition (as measured, for example, by the jump'' in C at {Tc}, {Delta}C({Tc})) and the magnitude of the low-temperature linear'' term in C, {gamma}(0)T, are correlated with concentration of these moments in the way expected for pair-breaking centers: {gamma}(0) increases and {Delta}C({Tc})/{Tc} decreases, both linearly, with increasing moment concentration. The contribution to {gamma}(0) associated with these pair-breaking centers, together with that previously recognized as arising from impurity phases, accounts completely for the observed {gamma}(0). We are not aware of other results that are inconsistent with these correlations, and conclude that there is no contribution to {gamma}(0) that is an intrinsic property of the superconducting state in YBCO. 3 refs., 3 figs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5555812
• Report Number(s): LBL-27541; CONF-890718--31; ON: DE90000166
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
IMPURITIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SPECIFIC HEAT
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES