Material Specification for TlGd:1222; [Tl(Pb)-Sr-Gd(Ce)-Cu-O]
Process: Solid State Reaction
Notes: "The various compositions... were prepared in two steps. Initially, a matrix of the nominal composition Gd2-xCexSr2Cu2Oy was prepared by heating a mixture of calculated amounts of Gd2O3, CeO2, SrCO3 and CuO at (about) 1200 K for 24 h. The freshly prepared matrix was then mixed with stoichiometric amounts of Tl2O3 and PbO2. The mixture, in the form of small bars, was then heated in alumina ampoules sealed inside a quartz tube at 1185 K for 6 h and then furnace-cooled down to room temperature... The as-synthesized samples were then annealed in oxygen at a pressure of (10 MPa = 100 bar) at 720 K for 12 h... A second annealing was carried out for another 12 h at the same temperature and pressure."
Formula: Tl0.5Pb0.5Sr2Gd2-xCexCu2O9-y
Informal Name: TlGd:1222
Chemical Family: Tl(Pb)-Sr-Gd(Ce)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for TlGd:1222; [Tl(Pb)-Sr-Gd(Ce)-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| x of Cex (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 0.0 |
296 |
3.839 |
-- |
29.586 |
| 0.2 |
296 |
3.840 |
-- |
29.532 |
| 0.4 |
296 |
3.843 |
-- |
29.509 |
| 0.6 |
296 |
3.846 |
-- |
29.455 |
Measurement Method: X-ray diffraction
"X-ray diffraction patterns wre registered using a Seifert vertical diffractometer equipped with a primary monochromator in order to select the CuKα
1 radiation. Data were collected in the range 10° ≤ 2θ ≤ 90° by step scanning with an increment of 0.02° in 2θ... Lattice constants and crystal structure refinements were done using the profile refinement program DBW 3.2."
Cautions: Evaluated Data
Critical Temperature for TlGd:1222; [Tl(Pb)-Sr-Gd(Ce)-Cu-O]
| x of Cex (formula units) |
Critical Temperature (K) |
| 0.0 |
0 |
| 0.1 |
30 |
| 0.2 |
45 |
| 0.3 |
45 |
| 0.4 |
45 |
| 0.5 |
30 |
| 06 |
0 |
Measurement Method: Ac susceptibility
"Magnetic measurements were carried out with a commercial AC Lakeshore susceptometer (B= 0.5 mT = 5 G) on the same samples before and after oxygen annealing. The calibration method used for the estimation of the volume fraction is by using a standard sample of chromium potassium alum. The volume fractions have been confirmed by a Quantum Design SQUID also."
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
