Material Specification for La:21; [La(Ba)-Cu-O]
Process: Solid State Reaction
Notes: "Samples... were prepared by mixing the prescribed amounts of La2O3, BaCO3 and CuO, all of which are 99.99% pure, and by reacting the pellets of the mixture at 900 °C in air for 24 h... the reacted pellets were powdered, pressed into pellets again, and sintered at 1100 °C in air for 2 h."
Formula: La1.85Ba0.15CuO4-x
Informal Name: La:21
Chemical Family: 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 La:21; [La(Ba)-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 12 |
3.7747 |
-- |
13.252 |
| 20 |
3.7747 |
-- |
13.244 |
| 37 |
3.7747 |
-- |
13.252 |
| 48 |
3.7747 |
-- |
13.244 |
| 52 |
3.7747 |
-- |
13.244 |
| 60 |
3.7739 |
-- |
13.257 |
| 71 |
3.7747 |
-- |
13.252 |
| 79 |
3.7747 |
-- |
13.244 |
| 90 |
3.7747 |
-- |
13.244 |
| 99 |
3.7747 |
-- |
13.252 |
| 117 |
3.7747 |
-- |
13.260 |
| 130 |
3.7756 |
-- |
13.256 |
| 139 |
3.7756 |
-- |
13.256 |
| 150 |
3.7756 |
-- |
13.263 |
| 161 |
3.7747 |
-- |
13.252 |
| 177 |
3.7756 |
-- |
13.256 |
| 191 |
3.7781 |
-- |
13.259 |
| 208 |
3.7773 |
-- |
13.262 |
| 228 |
3.7781 |
-- |
13.259 |
| 244 |
3.7781 |
-- |
13.266 |
| 259 |
3.7781 |
-- |
13.274 |
| 276 |
3.7789 |
-- |
13.270 |
Measurement Method: X-ray diffraction
"The powder X-ray diffraction analysis was carried out... the variations of the lattice parameters with temperature (were) determined from the (110) and (103) peaks." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 1 of the paper.
Critical Temperature for La:21; [La(Ba)-Cu-O]
| ΔTc (K) |
Tc(mid) (K) |
Critical Temperature (K) |
| 3.7 |
30.3 |
27 |
Measurement Method: Four-probe method
"The electrical resistivity was measured by a dc four-probe method, with the leads attached to the sample by silver paste." No additional measurement details were noted.
Cautions: Evaluated Data
Resistance (normal state) for La:21; [La(Ba)-Cu-O]
| Temperature (K) |
Resistance (normal state) (mΩ) |
| 26 |
0.0 |
| 27 |
0.1 |
| 28 |
3.5 |
| 30 |
12.1 |
| 30 |
20.5 |
| 31 |
24.8 |
| 32 |
29.6 |
| 34 |
31.7 |
| 35 |
32.2 |
| 37 |
32.9 |
| 39 |
32.6 |
| 40 |
33.3 |
| 42 |
33.6 |
| 48 |
34.7 |
Measurement Method: Four-probe method
"The electrical resistivity was measured by a dc four-probe method, with the leads attached to the sample by silver paste." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 2 of the paper.
Specific Heat for La:21; [La(Ba)-Cu-O]
| Temperature (K) |
Specific Heat (J kg-1 K-1) |
| 4 |
0.1 |
| 10 |
0.6 |
| 22 |
12 |
| 31 |
30 |
| 40 |
53 |
| 50 |
79 |
| 61 |
105 |
| 77 |
146 |
Measurement Method: Adiabatic heat pulse
"The specific heats... were measured by an adiabatic heat-pulse calorimeter at temperatures between 2 K and 80 K. A typical sample weight was 2 g." The authors determined the Debye temperature from the slope of the low temperature portion of the plot of C/T versus T
2, where C is the specific heat and T is the temperature. No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 4 of the paper.
Thermal Expansion for La:21; [La(Ba)-Cu-O]
| Direction () |
Temperature Range (K) |
Thermal Expansion (10-6 K-1) |
| a-axis |
120-300 |
3.5 |
| c-axis |
14-300 |
3.8 |
Measurement Method: X-ray diffraction
"The powder X-ray diffraction analysis was carried out... the variations of the lattice parameters with temperature (were) determined from the (110) and (103) peaks." No additional measurement details were noted.
Cautions: Evaluated Data
Debye Temperature for La:21; [La(Ba)-Cu-O]
| Debye Temperature (K) |
| 385 |
Measurement Method: Adiabatic heat pulse
"The specific heats... were measured by an adiabatic heat-pulse calorimeter at temperatures between 2 K and 80 K. A typical sample weight was 2 g." The authors determined the Debye temperature from the slope of the low temperature portion of the plot of C/T versus T
2, where C is the specific heat and T is the temperature. No additional measurement details were noted.
Cautions: Evaluated Data
Thermoelectric Power for La:21; [La(Ba)-Cu-O]
| Temperature (K) |
Thermoelectric Power (µV/K) |
| 4 |
0.0 |
| 28 |
0.0 |
| 30 |
10.0 |
| 35 |
20.0 |
| 46 |
25.0 |
| 74 |
30.0 |
| 100 |
31.6 |
| 150 |
31.6 |
| 200 |
30.3 |
Measurement Method: Thermopower measurement
"The thermal emf's were measured down to 2 K against chromel by a differential method using two sets of Au(Fe)-chromel thermocouples." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 3a of the paper.
