Material Specification for Tl:221; [Tl-Ba-Cu-O]
Process: Solid State Reaction
Notes: "We used Tl2Ba2O5 and CuO (Cerac, 99.9%) powder either directly (batch B) or after annealing for 3 days at 750 °C under (0.1 MPa =1 bar) O2 (batch A). After pressing the stoichiometric mixture under(0.5 GPa = 5 kbar), the pellets were given appropriate heat treatments, i.e. (1) reaction at 900-930 °C under (10 MPa = 100 bar) of oxygen during 30 min to obtain the orthorhombic, non-superconducting phase. The weight loss is somewhat below 0.8%. (2) reaction at 850 °C under (10 MPa = 100 bar) of argon or helium during 12 min, followed by regrinding and repeating the procedure twice, to form the tetragonal superconducting 2201 phase. A more significant weight loss of 1.5% is observed in this case."
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:
Crystallography for Tl:221; [Tl-Ba-Cu-O]
| Crystal System: | |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| Batch Number () |
Gas Preparation () |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| B |
helium |
296 |
3.8694(4) |
-- |
23.221(4) |
| B |
helium |
296 |
3.8674(3) |
-- |
23.218(3) |
| B |
argon |
296 |
3.8717(5) |
-- |
23.225(4) |
| A |
argon |
296 |
3.8706(4) |
-- |
23.224(3) |
| A |
argon |
296 |
3.8685(3) |
-- |
23.223(3) |
| A |
argon |
296 |
3.8700(3) |
-- |
23.226(2) |
| A |
argon |
296 |
3.8693(4) |
-- |
23.230(3) |
| A |
oxygen |
296 |
5.4467(8) |
5.4911(7) |
23.144(2) |
| A |
oxygen |
296 |
5.4470(6) |
5.4974(5) |
23.141(2) |
Measurement Method: X-ray diffraction
"The crystal structure was studied at ambient temperature by X-ray diffraction using a Guinier camera with CuKα radiation. Silicon was added to the powdered samples as an internal standard (a=5.4308 σ). The lattice parameters of the...orthorhombic and tetragonal phases were determined from least-squares fits using more than 20 lines (10° < 4θ < 160°). The lines were indexed according to the space group I4/mmm for the tetragonal phase and Ccc2 (A2aa) for the orthorhombic phase."
Cautions: Evaluated Data
Critical Temperature for Tl:221; [Tl-Ba-Cu-O]
| Batch Number () |
Gas Preparation () |
Critical Temperature (K) |
| B |
helium |
90.8 |
| B |
helium |
91.8 |
| B |
argon |
91.1 |
| A |
argon |
92.1 |
| A |
argon |
90.5 |
| A |
argon |
92.0 |
| A |
argon |
87.4 |
Measurement Method: Ac susceptibility
"The superconducting transitions were detected by means of a mutual inductance bridge operating between 80 and 800 Mz. The AC field amplitude was set in a first run to a low value of typically (4 A/m = 0.05 Oe) rms. The earth field is compensated by a screen of µ-metal." No additional measurement details were noted.
Cautions: Evaluated Data
Magnetic Susceptibility for Tl:221; [Tl-Ba-Cu-O]
| Magnetic Field (T) |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| 0 |
6 |
-0.78 |
| 0 |
22 |
-0.77 |
| 0 |
46 |
-0.75 |
| 0 |
67 |
-0.71 |
| 0 |
89 |
-0.49 |
| 0 |
99 |
0.00 |
| 0 |
100 |
0.00 |
| 0.05 |
34 |
-0.66 |
| 0.05 |
46 |
-0.61 |
| 0.05 |
57 |
-0.35 |
| 0.05 |
61 |
-0.18 |
| 0.05 |
67 |
-0.05 |
| 0.05 |
77 |
0.00 |
| 0.05 |
100 |
0.00 |
| 0.1 |
34 |
-0.63 |
| 0.1 |
46 |
-0.53 |
| 0.1 |
51 |
-0.32 |
| 0.1 |
58 |
-0.09 |
| 0.1 |
67 |
-0.01 |
| 0.1 |
89 |
0.00 |
| 0.1 |
100 |
0.00 |
| 0.2 |
28 |
-0.64 |
| 0.2 |
43 |
-0.43 |
| 0.2 |
46 |
-0.35 |
| 0.2 |
52 |
-0.13 |
| 0.2 |
62 |
-0.01 |
| 0.2 |
67 |
0.00 |
| 0.2 |
100 |
0.00 |
| 0.5 |
25 |
-0.63 |
| 0.5 |
34 |
-0.51 |
| 0.5 |
41 |
-0.22 |
| 0.5 |
45 |
-0.09 |
| 0.5 |
53 |
0.00 |
| 0.5 |
100 |
0.00 |
| 1 |
23 |
-0.60 |
| 1 |
32 |
-0.35 |
| 1 |
35 |
-0.15 |
| 1 |
41 |
-0.04 |
| 1 |
45 |
0.00 |
| 1 |
100 |
0.00 |
| 1.8 |
6 |
-0.72 |
| 1.8 |
16 |
-0.65 |
| 1.8 |
23 |
-0.50 |
| 1.8 |
28 |
-0.24 |
| 1.8 |
35 |
-0.07 |
| 1.8 |
39 |
0.00 |
| 1.8 |
100 |
0.00 |
Measurement Method: Ac susceptibility
"The superconducting transitions were detected by means of a mutual inductance bridge operating between 80 and 800 Mz. The AC field amplitude was set in a first run to a low value of typically (4 A/m = 0.05 Oe) rms. The earth field is compensated by a screen of µ-metal." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 6 of the paper.
Specific Heat for Tl:221; [Tl-Ba-Cu-O]
| Temperature (K) |
Specific Heat (J kg-1 K-1) |
| 65 |
10.2 |
| 67 |
10.6 |
| 71 |
11.2 |
| 75 |
12.0 |
| 80 |
12.8 |
| 88 |
13.9 |
| 92 |
14.5 |
| 96 |
15.1 |
| 100 |
15.4 |
| 104 |
15.9 |
| 105 |
16.1 |
| 107 |
16.2 |
Measurement Method: Adiabatic calorimeter
"The calorimeter used for this study is of the adiabatic, continuous heating type; the sample is in vacuo. Years of operation have confirmed an accuracy better than 1% using 0.5 g samples, whereas the scatter may be as low as 0.1% to 0.2%." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 12 of the paper.
Irreversibility Field for Tl:221; [Tl-Ba-Cu-O]
| Temperature (K) |
Irreversibility Field (T) |
| 50 |
1.8 |
| 55 |
1.0 |
| 61 |
0.5 |
| 67 |
0.2 |
| 73 |
0.09 |
| 77 |
0.05 |
Measurement Method: Ac susceptibility
"The superconducting transitions were detected by means of a mutual inductance bridge operating between 80 and 800 Mz. The AC field amplitude was set in a first run to a low value of typically (4 A/m = 0.05 Oe) rms. The earth field is compensated by a screen of µ-metal." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
