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 Tc in Superconducting Cuprates
Author(s): J. L. Tallon, J. Lusk, and M. R. Presland
Publication: Physica C Volume: 174 Issue: Not Available Year: 1991 Page(s): 345-351
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Critical Temperature

Materials and Properties

Tl:1212; [Tl(Pb)-Sr(La)-Ca-Cu-O]
Material Specification for Tl:1212; [Tl(Pb)-Sr(La)-Ca-Cu-O] Process: Solid State Reaction
Notes: "Samples... were prepared... by decomposing stoichiometric mixtures of the Ca, Sr and La nitrates together with CuO at 700 °C then mixing with a stoichiometric quantity of Tl2O3 and PbO, milling, die-pressing pellets and reacting in sealed gold tubes using AgO powder as a source of excess oxygen."
Formula: Tl0.5Pb0.5Sr2-xLaxCaCu2O7
Informal Name: Tl:1212
Chemical Family: Tl(Pb)-Sr(La)-Ca-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:1212; [Tl(Pb)-Sr(La)-Ca-Cu-O]
x of Lax (formula units) dTc/dp at R=0 (K/GPa) Critical Temperature (K)
0 1.05 ± 0.12 81.2
0.2 0.50 ± 0.03 100.5
0.4 1.32 ± 0.15 88.3
Measurement Method: Four-probe method
The authors cite J. L. Tallon et al., Physica C, Vol. 167, 236 (1990), and summarize the procedure as follows. "Samples with dimensions of 13 mm x 2.5 mm x 1.5 mm were cut and loops of tinned copper wire were attached using silver paint at the ends and at three intermediate locations. A copper-constantan thermocouple junction was soldered to the central loop. The samples and electrodes were then coated with high resistance varnish then wrapped in teflon tape. Four-terminal resistivity measurements were carried out at pressure vessel... with a heating rate through the superconducting transition of 0.25 K/min."

Cautions: Evaluated Data
The authors indicate an uncertainty for dTcdp of about 10%.