Material Specification for Tl:2234; [Tl-Ba-Ca-Cu-O]
Process: Solid State Reaction
Notes: "Starting materials were mixtures of Tl2O3, CaO, CuO and BaCuO2 with the metal ratio Tl:Ba:Ca:Cu=1:2:2:3 and 2:2:3:4. The mixture was pressed into a pellet form of 10 mm diameter and 1 mm thickness. The pellet was wrapped with gold foil and fired in a silica tube at around 895 °C for 50 min in a flow of O2. CaO was prepared by firing CaCO3 at 900 °C and preserved in the furnace at 900 °C to avoid the formation of calcium hydroxide. Reaction products were slowly cooled in a furnace in O2 atmosphere."
Formula: Tl2Ba2Ca3Cu4O12
Informal Name: Tl:2234
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:2234; [Tl-Ba-Ca-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 296 |
3.853(1) |
-- |
41.98(3) |
Measurement Method: X-ray diffraction
"X-ray powder diffraction patterns (were) measured with CuKα radiation... The unit cell dimensions for the tetragonal cell (were) determined by the least squares method..." No additional measurement details were noted.
Cautions: Evaluated Data
Critical Temperature for Tl:2234; [Tl-Ba-Ca-Cu-O]
| Tc(onset) (K) |
Critical Temperature (K) |
| 112 |
108 |
Measurement Method: Four-probe method
"The resistivity for a sintered sample was measured by a conventional four probe method with a measuring current of 1 mA." No additional measurement details were noted.
Cautions: Evaluated Data
Resistivity (normal state) for Tl:2234; [Tl-Ba-Ca-Cu-O]
| Temperature (K) |
Resistivity (normal state) (mΩ·cm) |
| 0.8 |
0.0 |
| 110 |
0.6 |
| 112 |
5.6 |
| 124 |
9.8 |
| 157 |
15.7 |
| 186 |
21.1 |
| 224 |
26.6 |
| 258 |
31.7 |
| 285 |
35.9 |
Measurement Method: Four-probe method
"The resistivity for a sintered sample 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 2 of the paper.
Magnetic Susceptibility for Tl:2234; [Tl-Ba-Ca-Cu-O]
| Cooling Condition () |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| FC |
4 |
-1.8 |
| FC |
30 |
-1.9 |
| FC |
50 |
-1.8 |
| FC |
84 |
-1.6 |
| FC |
107 |
-1.1 |
| FC |
112 |
0.0 |
| FC |
130 |
0.0 |
| ZFC |
8 |
-3.0 |
| ZFC |
25 |
-3.0 |
| ZFC |
49 |
-2.8 |
| ZFC |
82 |
-2.4 |
| ZFC |
102 |
-1.8 |
| ZFC |
108 |
-1.2 |
| ZFC |
111 |
-0.4 |
| ZFC |
114 |
0.0 |
Measurement Method: SQUID magnetometer
"The DC susceptibility measurement for the powdered sample was done in a magnetic field of (1.6 kA/m = 20 Oe) by using a SQUID magnetometer. The susceptibilities (were determined) after zero field cooling (ZFC) and on field cooling (FC)..."
Cautions: Evaluated Data
Digitized data were obtained from Figure 3 of the paper.
