Material Specification for Nd:21; [Nd(Ce)-Cu-O]
Process: Solid State Reaction
Notes: "The sample... was prepared by the solid state reaction technique. Prescribed amounts of Nd2O3 (99.9%), CeO2 (99.9%) and CuO (99.9%) were mixed and prereacted at 950°C for 12 h. The resulting powder was pressed into cylindrical pellets of diameter 8 mm and thickness about 2 mm. These pellets were sintered in air for 24 h at 1150 °C, from which temperature they were quenched. X-ray diffraction confirmed that the sample was single phase with a c/a ratio of 3.061, corresponding to a Ce concentration of 0.15... In order to induce superconductivity, the sample was annealed at 890 °C for 15 h in a N2 (4N5) flow. For studies of the thermal stability... against oxidation and reduction processes, the sample was placed in flows of pure oxygen (4N5) and nitrogen (4N5), respectively."
Formula: Nd1.85Ce0.15CuO4+x
Informal Name: Nd:21
Chemical Family: Nd(Ce)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Nd:21; [Nd(Ce)-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
I4/mmm |
Cell Parameters
| Occupancy (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| -- |
296 |
3.94270 |
-- |
12.0707 |
Atomic Coordinates
| Occupancy (formula units) |
Atom |
Temp
K
|
a-axis |
b-axis |
c-axis |
| 4 |
Nd/Ce |
296 |
0 |
0 |
0.35282 |
| 2 |
Cu |
296 |
0 |
0 |
0 |
| 4 |
O(1) |
296 |
0 |
0.5 |
0 |
| 4.04(9) |
O(2) |
296 |
0 |
0.5 |
0.25 |
Measurement Method: Neutron diffraction
"Neutron diffraction experiments were carried out by use of the multi-detector powder neutron diffractometer at the DR3 reactor at Riso National Laboratory. The diffractometer has twenty detectors separated by 5.288°, giving a total of 2000 data points for one hundred instrumental settings. It was equipped with a germanium crystal of 11' mosaicity as monochromator. An incident neutron wavelength of... 1.07 σ was chosen..."
Cautions: Evaluated Data
Critical Temperature for Nd:21; [Nd(Ce)-Cu-O]
| Critical Temperature (K) |
| 22 |
Measurement Method: SQUID magnetometer
"The DC magnetic susceptibility measurements (were) performed using a SHE SQUID magnetometer in an external field of (1.25 kA/m = 15.7 Oe) after field cooling." No additional measurement details were noted.
Cautions: Evaluated Data
Magnetic Susceptibility for Nd:21; [Nd(Ce)-Cu-O]
| Oxidation Time () |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| 15 |
5.3 |
-12.9 |
| 15 |
6.3 |
-12.9 |
| 15 |
8.0 |
-11.9 |
| 15 |
11.1 |
- 7.4 |
| 15 |
13.9 |
- 0.6 |
| 15 |
15.9 |
0.9 |
| 15 |
22.9 |
1.1 |
| 30 |
5.1 |
- 5.1 |
| 30 |
6.1 |
- 5.1 |
| 30 |
7.9 |
- 3.6 |
| 30 |
11.2 |
0.2 |
| 30 |
12.9 |
1.3 |
| 30 |
20.9 |
1.3 |
| 30 |
24.9 |
1.1 |
| 30 |
29.9 |
1.0 |
| 45 |
4.6 |
- 2.6 |
| 45 |
7.1 |
- 2.4 |
| 45 |
9.2 |
- 0.2 |
| 45 |
10.9 |
1.6 |
| 45 |
13.9 |
1.9 |
| 45 |
21.7 |
1.5 |
| 45 |
27.9 |
1.4 |
| 60 |
6.2 |
1.6 |
| 60 |
7.9 |
1.8 |
| 60 |
10.9 |
1.8 |
| 60 |
14.9 |
1.5 |
| 60 |
19.9 |
1.3 |
| 60 |
25.9 |
1.1 |
| 60 |
27.9 |
0.8 |
Measurement Method: SQUID magnetometer
"The DC magnetic susceptibility measurements (were) performed using a SHE SQUID magnetometer in an external field of (1.25 kA/m = 15.7 Oe) after field cooling." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 5 of the paper.
Thermoelectric Power for Nd:21; [Nd(Ce)-Cu-O]
| Temperature (K) |
Thermoelectric Power (µV/K) |
| 23 |
0.09 |
| 26 |
0.07 |
| 33 |
0.11 |
| 38 |
0.09 |
| 50 |
0.11 |
| 100 |
0.20 |
| 200 |
0.62 |
| 300 |
1.09 |
Measurement Method: Thermopower method
The authors cite P.M. Chaikin et al., Rev. Sci. Instr., Vol. 46, 218 (1975), and summarize the procedure as follows. "The thermoelectric power, S, was measured using a slow AC-technique... The sample experiences an alternating temperature gradient with a maximum decrease along the long axis of the sample of ±0.5 K... it is estimated that the accuracy of the measurement is ±0.05 µV/K."
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
