Material Specification for CaLa:123; [Ca-La(Ba)-Cu-O]
Process: Solid State Reaction
Notes: "Powders... were obtained using two methods for precursor preparation. The first method was a mixed oxide route. Mixtures of Ca(NO3)2•4H2O, Ba(OH2•8H2O, La(NO3)3•xH2O and CuO were dried at 200 °C and subsequently mixed for two hours in an agate ball mill with hexane. After evaporation of the solvent at 100 °C, the mixture was fired in air for 6 h at 950 °C and subsequently cooled to room temperature (100 °C/h). The second method used is a spray drying technique. Appropriate ratios of calcium, barium, lanthanum and copper nitrates were dissolved in water and the solution was spray-dried in hot air heated to about 200 °C (Buchi Spray Dryer 190). The mixed nitrates were collected and fired in air for 1 h directly at 950 °C. After regrinding the samples were fired for another 5 h. The... powders were then cold pressed at (10.1 MPa = 100 atm). The resulting discs were fired in oxygen (0.1 MPa = 1 atm) at 980 °C for one hour and subsequently slowly cooled to room temperature (12 °C/h)."
Formula: CaLaBaCu3O7-x
Informal Name: CaLa:123
Chemical Family: Ca-La(Ba)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for CaLa:123; [Ca-La(Ba)-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
P4/mmm
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 25 |
3.886 |
-- |
11.636 |
| 150 |
3.878 |
-- |
11.674 |
| 300 |
3.886 |
-- |
11.702 |
| 400 |
3.891 |
-- |
11.715 |
| 700 |
3.899 |
-- |
11.778 |
| 900 |
3.907 |
-- |
11.814 |
| 1025 |
3.919 |
-- |
11.890 |
| 1050 |
3.919 |
-- |
11.898 |
| 1100 |
3.918 |
-- |
11.900 |
Measurement Method: X-ray diffraction
"The lattice constants (were) determined by high temperature X-ray diffraction (monochromatized CuK
α). The samples were heated in pure oxygen of (0.1 MPa = 1 atm)." No additional measurement details were noted.
Cautions: Unevaluated Data
Digitized data were obtained from Figure 1 of the paper.
Critical Temperature for CaLa:123; [Ca-La(Ba)-Cu-O]
| Critical Temperature (K) |
| 80 |
Measurement Method: Electrical resistance
"Electrical reistance as a function of temperature was determined via a four-point resistance measurement with DC currents of 1 mA to 40 mA." No additional measurement details were noted.
Cautions: Unevaluated Data
