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NIST High Temp. Superconducting Materials (HTS) Database:

NIST Standard Reference Database 62

Last Update to Data Content: 1996

DOI: https://doi.org/10.18434/T4KP8J

Bibliographic Information

Title: Thermal Conductivity of YBa2Cu3O7-δ from Ambient to 1150 K
Author(s): C.G.S. Pillai
Publication: Solid State Communications Volume: 80 Issue: 4 Year: 1991 Page(s): 277-280
Editor(s): Not Available
Publisher: Pergamon Press Ltd
Language: English
Notes: Not Available
Keywords: Material Specification, Thermal Conductivity

Materials and Properties

Y:123; [Y-Ba-Cu-O]
Material Specification for Y:123; [Y-Ba-Cu-O] Process: Solid State Reaction
Notes: "The samples... were prepared by solid state reaction of thoroughly ground mixtures of high-purity powders of Y2O3, BaCO3 and CuO taken in the required stoichiometry. The ground mixture was initially heated at 1173 K in air for a period of 16 h. After regrinding, the product was reheated at 1173 K for a further period of 16 h. The processes were repeated a few times to ensure the completion of the reaction. Cylindrical samples of 2.5 cm in diameter and (about) 2 cm in height required for the thermal conductivity measurements were prepared by uniaxial cold compaction of the powder followed by sintering overnight at 1223 K in air and cooling at the rate of 2 K min-1. The sintering was then repeated in flowing oxygen."
Formula: YBa2Cu3O7-x
Informal Name: Y:123
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Thermal Conductivity for Y:123; [Y-Ba-Cu-O]
Temperature (K) Thermal Conductivity (W m-1 K-1)
314 2.9
361 2.9
397 2.9
421 3.0
456 2.9
492 2.9
539 2.9
551 3.0
598 3.0
640 3.0
646 3.0
705 3.1
741 3.2
795 3.3
860 3.6
938 3.7
992 4.0
1046 4.3
1088 4.5
1142 5.0
Measurement Method: Steady-state heat flow
The authors cite C.G.S. Pillai et al., Int. J. Thermophysics, Vol. 12(3), 563 (1991), and summarize the procedure as follows. "The thermal conductivity of the samples were measured by a steady state axial heat flow comparative apparatus. In this the sample is inserted between two identical reference materials (pyroceram-9606) having the same diameter as that of the sample. An axial heat flow is established through this three-element stack by sandwiching it between a heat source and a sink. The conductivity of the sample is determined from the thermal conductivities of the references and the measured temperature gradients of the sample and the references. ... The accuracy of the measurements is within ±3%."

Cautions: Evaluated Data
"The thermal conductivity of the sample...measured in air showed a nearly temperature independent (plateau) behaviour up to around 650 K and thereafter increased linearly with a change of slope at around 925 K....Measurements carried out in oxygen atmosphere showed an identical behavior except that the plateau extended up to around 740 K and the change of slope was observed at around 975 K....The temperature at which the change of slope occurred at the end of the linear region coincides with the orthorhombic to tetragonal crystallographic transition reported for the oxide." Digitized data were obtained from Figure 1 of the paper.