Low-temperature specific heat of YBa/sub 2/Cu/sub 3/O/sub 7/, YBa/sub 2/Cu/sub 3/O/sub 6/, Y/sub 2/BaCuO/sub 5/, YBa/sub 3/Cu/sub 2/O/sub 7/, BaCuO/sub 2/, and CuO

Journal Article · Tue Nov 01 00:00:00 EST 1988 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00681980· OSTI ID:6051868

Eckert, D; Junod, A; Bezinge, A; Graf, T; Muller, J

The authors have measured the low-temperature specific heat (1.3 less than or equal to T less than or equal to 20 K) and the dc magnetic susceptibility (100 less than or equal to T less than or equal to 250 K) of eight samples of the high-T/sub c/ superconductor Y/sub x/Ba/sub 3-x/Cu/sub 3/O/sub 7-delta/ (x = 0.9, 1.0, 1.1) and of two samples of nonsuperconducting YBa/sub 2/Cu/sub 3/O/sub 6 + ..gamma../. They have also performed specific heat measurements on the possible impurity phases: YBa/sub 3/Cu/sub 2/O/sub 7/, Y/sub 2/BaCuO/sub 5/, CuO, and BaCuO/sub 2+x/. The superconducting samples all have a nonzero, sample-dependent linear term ..gamma..* and an upturn in C/T at very low temperature. They show that this anomalous behavior is at least partly due to the presence of a small amount (/approximately/ 1%) of BaCuO/sub 2+x/ impurity phase in the measured sample. This is evidenced by the correlation between ..gamma..* and the Curie component of the susceptibility, which is proportional to the amount of paramagnetic impurities.

• Research Organization: Universite de Geneva (Switzerland)
• OSTI ID: 6051868
• Journal Information: J. Low Temp. Phys.; (United States), Vol. 73:3-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
SPECIFIC HEAT
COPPER OXIDES
YTTRIUM OXIDES
ANNEALING
CHEMICAL COMPOSITION
CRYSTAL LATTICES
CURIE-WEISS LAW
DEBYE TEMPERATURE
IMPURITIES
MAGNETIC SUSCEPTIBILITY
PARAMAGNETISM
PHASE STUDIES
SINTERING
STOICHIOMETRY
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FABRICATION
HEAT TREATMENTS
MAGNETIC PROPERTIES
MAGNETISM
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies