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: Chemical Characterization and Superconductivity of Tl2Ba2-xLaxCuOy with the Orthorhombic and Tetragonal Structures
Author(s): S. Nakajima, T. Oku, R. Suzuki, M. Kikuchi, K. Hiraga, and Y. Syono
Publication: Physica C Volume: 214 Issue: Not Available Year: 1993 Page(s): 80-86
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature, Resistivity (normal state)

Materials and Properties

Tl:221; [Tl-Ba(La)-Cu-O]
Material Specification for Tl:221; [Tl-Ba(La)-Cu-O] Process: Solid State Reaction
Notes: "Mixtures of Tl2O3, BaO2, La2O3 and CuO... were pressed into pellets, 10-25 mm in diameter and 1 mm in thickness. The pellets were wrapped with a gold foil and fired at about 900 °C for several minutes in a flowing oxygen gas, and then cooled to room temperature at a rate of 10-15 °C/min... The starting composition having Tl:Ba:Ca:Cu = 2.5:2.0:0.0:1.0 and heated at 890 °C for 7 min resulted in an orthorhombic phase. The composition 2.0:2.0:0.0:1.0 heated at 890 °C for 7 min resulted in a tetragonal phase."
Formula: Tl2Ba2-xLaxCuO6-y
Informal Name: Tl:221
Chemical Family: Tl-Ba(La)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Crystallography for Tl:221; [Tl-Ba(La)-Cu-O]
Crystal System:
Formula Units per Cell:
Space Group:
Cell Parameters
Phase () x of Lax (formula units) Temp K a Å b Å c Å
orthorhmbc 0.0 296 5.446 5.506 23.19
orthorhmbc 0.1 296 5.446 5.504 23.13
orthorhmbc 0.15 296 5.455 5.504 23.14
orthorhmbc 0.20 296 5.450 5.508 23.12
tetragonal 0.0 296 3.863 -- 23.18
tetragonal 0.1 296 3.863 -- 23.14
tetragonal 0.2 296 3.865 -- 23.10
tetragonal 0.3 296 3.867 -- 23.05
tetragonal 0.4 296 3.865 -- 22.99
Measurement Method: X-ray diffraction
"The samples were examined by X-ray powder diffraction... using CuKα radiation. The unit cell dimensions were determined from the observed d-spacings of about sixteen reflections by the least squares method."

Cautions: Evaluated Data
Critical Temperature for Tl:221; [Tl-Ba(La)-Cu-O]
Phase () x of Lax (formula units) Critical Temperature (K)
orthorhmbc 0.0 0
orthorhmbc 0.1 36
orthorhmbc 0.15 47
orthorhmbc 0.2 49
tetragonal 0.0 0
tetragonal 0.1 30
tetragonal 0.2 39
tetragonal 0.3 37
tetragonal 0.4 43
Measurement Method: Four-probe method
"The resistivity was measured by a conventional four-probe method with a measuring current of 1 mA." No additional measurement details were noted.

Cautions: Evaluated Data
Digitized data were obtained from Figures 9 and 10 of the paper.
Resistivity (normal state) for Tl:221; [Tl-Ba(La)-Cu-O]
Phase () x of Lax (formula units) Temperature (K) Resistivity (normal state) (mΩ·cm)
orthorhmbc 0 3 0.3
orthorhmbc 0 52 0.6
orthorhmbc 0 91 0.8
orthorhmbc 0 109 0.7
orthorhmbc 0 150 1.0
orthorhmbc 0.1 23 0
orthorhmbc 0.1 57 1.3
orthorhmbc 0.1 89 1.5
orthorhmbc 0.1 115 1.7
orthorhmbc 0.1 150 2.3
orthorhmbc 0.15 42 0.0
orthorhmbc 0.15 46 2.3
orthorhmbc 0.15 55 4.1
orthorhmbc 0.15 75 4.8
orthorhmbc 0.15 106 5.4
orthorhmbc 0.15 129 5.9
orthorhmbc 0.15 151 6.6
orthorhmbc 0.2 45 0.0
orthorhmbc 0.2 50 4.3
orthorhmbc 0.2 52 8.1
orthorhmbc 0.2 54 10.1
orthorhmbc 0.2 61 11.5
orthorhmbc 0.2 90 12.7
orthorhmbc 0.2 118 13.9
orthorhmbc 0.2 143 15.0
Measurement Method: Four-probe method
"The resistivity was measured by a conventional four-probe method with a measuring current of 1 mA." No additional measurement details were noted.

Cautions: Evaluated Data
Digitized data were obtained from Figure 8 of the paper.