Material Specification for Tl:2223; [Tl-Ba-Ca-Cu-O]
Process: Solid State Reaction
Notes: "High-purity powders of Tl2O3, BaO2, CaO and CuO were weighed in the appropriate proportions... The powders were then mixed using a mortal and pestle and pressed into a pellet (10 mm diam. and 3 mm in thickness)... The pellets were wrapped in gold foil to prevent loss of thallium at elevated temperatures, then sintered at 910 °C for 3 h in oxygen. After sintering, the furnace was cooled to room temperature at a rate of 5 °C/min... The sample was wrapped in gold foil, encapsulated in an evacuated... quartz tube and annealed at 750 °C for 10 days. The resulting sample was then annealed in 0.2% and 2% oxygen/nitrogen atmosphere at 600 °C for 2 h and rapidly quenched into liquid nitrogen."
Formula: Tl1.6Ba2Ca2.4Cu3O10-x
Informal Name: Tl:2223
Chemical Family: Tl-Ba-Ca-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Tl:2223; [Tl-Ba-Ca-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
P4/mmm |
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 296 |
3.857 |
3.857 |
35.67 |
Measurement Method: X-ray diffraction
"X-ray diffraction (XRD) analyses were performed using a Philips PW1710 X-ray diffractometer with a CuKα radiation."
Cautions: Evaluated Data
Critical Temperature for Tl:2223; [Tl-Ba-Ca-Cu-O]
| Tc(magnetic) (K) |
Critical Temperature (K) |
| 128 |
124.5 |
Measurement Method: Four-probe method
"A standard four point probe method was used for the electrical resistivity measurements. The electrical contacts to the sample were made by fine copper wires with a conductive silver paint; the applied current was 1 mA. The temperature was recorded using a calibrated (accuracy ± 0.01 °C) silicon diode sensor located close to the sample."
Cautions: Evaluated Data
The authors indicated that T
c was determined from the temperature of zero resistance, and T
c(magnetic) was determined from the onset of diamagnetism in ac susceptibility measurements.
