Hts Logo

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: Anisotropic Thermoelectric Power in YBa2Cu3O7-x Single Crystals under Pressures up to 8 GPa
Author(s): S.K. Ramasesha, A.K. Singh, and P. Murugaraj
Publication: Physical Review B Volume: 43 Issue: 10 Year: 1991 Page(s): 8620-8622
Editor(s): Not Available
Publisher: American Physical Society
Language: English
Notes: Not Available
Keywords: Material Specification, Thermoelectric Power

Materials and Properties

Y:123; [Y-Ba-Cu-O]
Material Specification for Y:123; [Y-Ba-Cu-O] Process: Crystal Growth
Notes: The authors cite P. Murugaraj et al., Solid State Commun., Vol. 71, 167 (1989), and summarize the procedure as follows. "single crystals were grown... The value of x by spectroscopic method was found to be 0.05... Since the samples were thick... it is likely that the oxygen concentration in the interior was much lower than that detected at the surface. During the sample preparation for TEP measurements... the top layers of the as-prepared samples were removed exposing the crystal region of lower oxygen content. Comparison of the present TEP values at 300 K and one atmosphere with those obtained in other studies indicates that the oxygen content in the present samples was close to 6.8 ... The crystals measuring approximately 1.5x4 mm2 (ab plane) and 0.4 mm along the c axis were used in the present studies."
Formula: YBa2Cu3O7-x
Informal Name: Y:123
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Single Crystal
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Thermoelectric Power for Y:123; [Y-Ba-Cu-O]
Direction () Pressure (GPa) Thermoelectric Power (µV/K)
ab-plane 0.0 10.8
ab-plane 0.2 10.0
ab-plane 1.2 8.5
ab-plane 1.7 8.4
ab-plane 2.8 6.7
ab-plane 3.0 6.7
ab-plane 3.4 5.6
ab-plane 3.7 5.6
ab-plane 4.3 5.5
ab-plane 4.5 4.6
ab-plane 5.2 4.2
ab-plane 5.5 3.2
ab-plane 6.2 3.5
ab-plane 6.8 3.1
ab-plane 7.4 3.0
ab-plane 7.6 2.7
c-axis 0.6 22.2
c-axis 1.0 29.0
c-axis 1.0 29.6
c-axis 1.6 30.0
c-axis 2.2 29.0
c-axis 4.0 24.7
c-axis 6.7 18.5
c-axis 7.2 17.6
Measurement Method: Thermopower measurement
"A pair of tungsten carbide opposed anvil set-up (12.5-mm flat face) was used to generate pressure... A crystal... was placed at the central hole of a pyrophyllite gasket with the ab plane of the crystal (parallel to the plane of the gasket) and the annular gap filled with talc-epoxy mixture. The gasket-specimen assembly was thinned down to 0.27 mm by working both sides of the gasket on 600-grade emery paper. The specimen was separated from the anvils by sandwiching the gasket-specimen assembly between two prophyllite gaskets (0.3 mm thick) with talc discs at the center. A temperature gradient in the ab plane was set up by placing a 0.1-mm diameter heater wire near one end of the specimen. The thermo-emfs were measured at two points 1 mm apart, situated symmetrically about the center of the cell, across the two chromel (V ) and the two alumel (V ) wires of the chromel-alumel thermocouples. The TEP along the c axis... was measured using a similar cell but the temperature gradient was set up along the axis of the anvil by heating the lower anvil..."

Cautions: Evaluated Data
Digitized data were obtained from Figures 1 and 2 of the paper.