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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: Pressure Dependence of the Superconducting Transition Temperature of Tl2Ba2CuO6+δ for δ (approaching) 0
Author(s): J.E. Schirber, D.L. Overmyer, E.L. Venturini, D.S. Ginley, and B. Morosin
Publication: Physica C Volume: 193 Issue: Not Available Year: 1992 Page(s): 126-128
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Critical Temperature, Magnetic Susceptibility

Materials and Properties

Tl:221; [Tl-Ba-Cu-O]
Material Specification for Tl:221; [Tl-Ba-Cu-O] Process: Solid State Reaction
Notes: "Samples were prepared by thoroughly mixing stoichiometric portions of Tl2O3, CuO and BaO in a dry Ar atmosphere. The mixture was loaded in a dry box into a pressure vessel and reacted under (30 MPa = 0.3 kbar) Ar at 850 °C for 3 h."
Formula: Tl2Ba2CuO6+x
Informal Name: Tl:221
Chemical Family: Tl-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Critical Temperature for Tl:221; [Tl-Ba-Cu-O]
dTc/dp (K/GPa) Critical Temperature (K)
2 92
Measurement Method: Susceptibility method
The authors cite L.J. Azevedo et al., Phys. Rev. B, Vol. 30, 1370 (1984), and summarize the procedure as follows. "The superconducting transition temperature was defined as the onset of the Meissner diamagnetism measured in a SHE SQUID magnetometer (in a field of 1 mT)... The pressure dependence of Tc was obtained from measurements in an RF impedance system... The onset of the signature given for Tc by this technique has been demonstrated to correlate closely with that obtained on the same samples in the SQUID magnetometer... Pressures were generated in gaseous He and so for these experiments near 90 K, conditions are purely hydrostatic."

Cautions: Evaluated Data
Magnetic Susceptibility for Tl:221; [Tl-Ba-Cu-O]
Temperature (K) Magnetic Susceptibility (arbitrary)
5 -0.070
20 -0.069
40 -0.069
60 -0.067
80 -0.061
85 -0.057
87 -0.048
89 -0.022
90 -0.008
91 0.000
100 0.000
Measurement Method: Susceptibility method
The authors cite L.J. Azevedo et al., Phys. Rev. B, Vol. 30, 1370 (1984), and summarize the procedure as follows. "The superconducting transition temperature was defined as the onset of the Meissner diamagnetism measured in a SHE SQUID magnetometer (in a field of 1 mT)... The pressure dependence of Tc was obtained from measurements in an RF impedance system... The onset of the signature given for Tc by this technique has been demonstrated to correlate closely with that obtained on the same samples in the SQUID magnetometer... Pressures were generated in gaseous He and so for these experiments near 90 K, conditions are purely hydrostatic."

Cautions: Evaluated Data
Digitized data were obtained from Figure 2 of the paper.