Material Specification for Tl:221; [Tl-Ba-Cu-O]
Process: Solid State Reaction
Notes: The authors cite Y. Shimakawa et al., Phys. Rev. B, Vol. 40, 11400 (1989), and summarize the procedure as follows. "The three samples... were prepared by solid-state reactions... Since Tl-2201 tends towards Cu excess, the starting compositional ratio was set at Tl:Ba:Cu=2:2:1.1 to obtain single-phase samples. The oxygen contents in the samples were adjusted by changing annealing conditions... the samples are referred to as A (0 K), B (46 K) and C (79 K)."
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: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
I4/mmm
|
Cell Parameters
| Sample Number () |
Pressure (GPa) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| A |
0 |
296 |
3.86368(4) |
-- |
23.1392(4) |
| A |
0.124 |
296 |
3.86158(5) |
-- |
23.1282(5) |
| A |
0.249 |
296 |
3.85965(4) |
-- |
23.1186(4) |
| A |
0.373 |
296 |
3.85777(4) |
-- |
23.1094(4) |
| A |
0.497 |
296 |
3.85580(5) |
-- |
23.0995(5) |
| A |
0.626 |
296 |
3.85390(4) |
-- |
23.0901(4) |
| B |
0 |
296 |
3.86548(5) |
-- |
23.1949(5) |
| B |
0.124 |
296 |
3.86332(4) |
-- |
23.1836(4) |
| B |
0.248 |
296 |
3.86114(5) |
-- |
23.1728(5) |
| B |
0.372 |
296 |
3.85920(5) |
-- |
23.1633(5) |
| B |
0.498 |
296 |
3.85715(5) |
-- |
23.1525(5) |
| B |
0.622 |
296 |
3.85519(5) |
-- |
23.1435(5) |
| C |
0 |
296 |
3.86624(5) |
-- |
23.2263(5) |
| C |
0.124 |
296 |
3.86398(5) |
-- |
23.2147(5) |
| C |
0.249 |
296 |
3.86185(5) |
-- |
23.2040(5) |
| C |
0.372 |
296 |
3.85993(5) |
-- |
23.1914(5) |
| C |
0.497 |
296 |
3.85784(5) |
-- |
23.1832(5) |
| C |
0.622 |
296 |
3.85590(5) |
-- |
23.1738(5) |
Atomic Coordinates
| Sample Number () |
Pressure (GPa) |
Atom |
Temp
K
|
a-axis |
b-axis |
c-axis |
| C |
0 |
Tl/Cu |
296 |
0 |
0 |
0.29729 |
| C |
0 |
Ba |
296 |
0 |
0 |
0.08354 |
| C |
0 |
Cu |
296 |
0 |
0 |
0.5 |
| C |
0 |
O(1) |
296 |
0 |
0.5 |
0 |
| C |
0 |
O(2) |
296 |
0 |
0 |
0.38291 |
| C |
0 |
O(3) |
296 |
0 |
0.0929 |
0.21043 |
| C |
0 |
O(4) |
296 |
0 |
0.5 |
0.2728 |
| C |
0.622 |
Tl/Cu |
296 |
0 |
0 |
0.29729 |
| C |
0.622 |
Ba |
296 |
0 |
0 |
0.08363 |
| C |
0.622 |
Cu |
296 |
0 |
0 |
0.5 |
| C |
0.622 |
O(1) |
296 |
0 |
0.5 |
0 |
| C |
0.622 |
O(2) |
296 |
0 |
0 |
0.38325 |
| C |
0.622 |
O(3) |
296 |
0 |
0.0899 |
0.21022 |
| C |
0.622 |
O(4) |
296 |
0 |
0.5 |
0.272 |
Measurement Method: Neutron diffraction
The authors cite J.D. Jorgensen et al., Physica C, Vol. 171, 93 (1990), and summarize the procedure as follows. "(Time of Flight) TOF neutron diffraction data of samples A, B, and C were measured on the Special Environment Powder Diffraction (SEPD) at Argonne's Intense Pulsed Neutron Source. The samples were contained in a pressure cell constructed from three concentric cylinders of 7075-T6 alloy aluminum. With this cell using helium gas as the pressure transmitting medium, the pressure can be precisely controlled and measured under perfect hydrostatic conditions. For each sample, intensity data were collected at room temperature for about 3 h at six different pressures up to 0.622 GPa using detector banks at a 2θ value of 90° where collimation can be optimized to eliminate scattering from the pressure cell."
Cautions: Evaluated Data
Critical Temperature for Tl:221; [Tl-Ba-Cu-O]
| Sample Number () |
Critical Temperature (K) |
| A |
0 |
| B |
46 |
| C |
79 |
Measurement Method: Ac susceptibility
Cautions: Unevaluated Data
No measurement details were noted.
