Material Specification for LaBa:336; [La-Ba(Ca)-Cu-O]
Process: Solid State Reaction
Notes: "The starting compounds were high purity CaCO3, CuO, BaCO3 and La2O3. The first firing was done on a finely mixed powder at 900 °C for 12 h under air. The cooling rate was set to 5 °C/min down to 600 °C. Furnace cooling then took the compound to about 200 °C in several hours. The resulting black powder was removed from the furnace, reground, and pressed into a disc shaped pellet under a pressure of approximately 1.7x108 N/m2. The resulting pellets had a diameter of about 12 mm and a thickness of approximately 1.3 mm. The pellets were placed in an alumina boat which was placed inside a quartz firing tube. Oxygen was set to flow at a slow rate as the compounds were sintered for 24 h at 1000 °C. The cooling rate was the same as described earlier."
Formula: La3Ba3CaxCu6+xOy
Informal Name: LaBa:336
Chemical Family: La-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 LaBa:336; [La-Ba(Ca)-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| x of Cax (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 0 |
296 |
3.9096 |
-- |
11.7200 |
| 0.25 |
296 |
3.8997 |
-- |
11.6996 |
| 0.5 |
296 |
3.8892 |
-- |
11.6590 |
| 0.75 |
296 |
3.8798 |
-- |
11.6400 |
| 1.0 |
296 |
3.8797 |
-- |
11.6197 |
| 2.0 |
296 |
3.8699 |
-- |
11.5987 |
| 3.0 |
296 |
3.8700 |
-- |
11.5994 |
Measurement Method: X-ray diffraction
"The X-ray diffraction patterns were obtained after the pellets were tested for superconductivity and reground to a fine powder. The CuKα line was utilized in a Phillips X-ray Diffraction Analyser System 1840 to obtain the diffraction spectrum."
Cautions: Evaluated Data
Digitized data were obtained from Figures 3 and 4 of paper.
Critical Temperature for LaBa:336; [La-Ba(Ca)-Cu-O]
| x in Lax (formula units) |
Critical Temperature (K) |
| 0.0 |
0 |
| 0.3 |
5 |
| 0.5 |
42 |
| 0.7 |
69 |
| 0.9 |
79 |
| 1.0 |
80 |
| 2.0 |
80 |
| 3.0 |
81 |
Measurement Method: Ac susceptibility
"The onset of the transition is seen in the out of phase component... The minimum in the out of phase voltage is more easily picked out..." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
