Material Specification for Gd:123; [Gd-Ba-Sr-Cu-O]
Process: Solid State Reaction
Notes: "A special preparation process has been developed to stabilize GdBaSrCu3O7-x compounds in both tetragonal and orthorhombic structures with oxygen deficiency x close to zero. "(Specimens) were prepared by the conventional solid-state reaction methods. Stoichiometric amounts of Gd2O3, BaCo3, SrSO3, and CuO, with purity better than 99.9% were ground in an agate ball mill for one hour and pressed into pellets at a pressure of 600 MPa. The first calcination was carried out in air at 920°C for 24 h. After furnace cooling down to room temperature, the calcined pellets were gorund for another hour and pelletised again. The second calcination was carried out at 940°C for 24 h under oxygen atmosphere. The cooling rate down to room temperature was less than 100°C per hour in oxygen atmosphere. Further thermal treatment...was made in two steps: firstly, for oxygen desorption, a treatment in argon atmosphere at 940°C for two hours followed by cooling down to room temperature, secondly, an annealing process in oxygen atmosphere at different temperatures for each sample, varying from 400°C to 950°C. The time for annealing was 12 h at the maximum temperature, the cooling rate down to room temperature was less than 100°C per hour. The oxygen content of all samples...was determined by iodometric titration analysis..."
Formula: GdBaSrCu3Ox
Informal Name: Gd:123
Chemical Family: Gd-Ba-Sr-Cu-O
Chemical Class: Oxide
Structure Type:
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Gd:123; [Gd-Ba-Sr-Cu-O]
| Crystal System: | |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| Phase () |
x of Ox (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| Tetragonal |
7.00 |
296 |
3.839 |
-- |
11.572 |
| Orthorhomb |
6.94 |
296 |
3.804 |
3.863 |
11.588 |
Measurement Method: X-ray diffraction
"Structural determination was carried out by the powder XRD technique at room temperature using CuKα radiation. The instrument was calibrated by silicon powder. Lattice parameters were calibrated by using a least-squares refinement."
Cautions: Evaluated Data
Resistivity (normal state) for Gd:123; [Gd-Ba-Sr-Cu-O]
| Phase () |
x of Ox (formula units) |
Temperature (K) |
Resistivity (normal state) (mΩ·cm) |
| tetragonal |
7.00 |
83 |
0.01 |
| tetragonal |
7.00 |
85 |
0.19 |
| tetragonal |
7.00 |
83 |
0.46 |
| tetragonal |
7.00 |
85 |
0.78 |
| tetragonal |
7.00 |
87 |
0.99 |
| tetragonal |
7.00 |
100 |
1.10 |
| tetragonal |
7.00 |
150 |
1.35 |
| tetragonal |
7.00 |
200 |
1.55 |
| tetragonal |
7.00 |
250 |
1.77 |
| tetragonal |
7.00 |
300 |
1.97 |
| orthorhom |
6.94 |
83 |
0.01 |
| orthorhom |
6.94 |
85 |
0.19 |
| orthorhom |
6.94 |
87 |
0.32 |
| orthorhom |
6.94 |
100 |
0.35 |
| orthorhom |
6.94 |
150 |
0.45 |
| orthorhom |
6.94 |
200 |
0.54 |
| orthorhom |
6.94 |
250 |
0.61 |
| orthorhom |
6.94 |
300 |
0.68 |
Measurement Method: Five-probe method
"The transport measurements were performed on thin, bar-shaped samples, which were cut from the ceramic pellets. Contacts were established in the usual five-probe geometry with Ag paste and gold wires. The measurements were carried out in a closed-cycle refrigerator. Temperature was controlled by a platinum resistor and precision temperature measurements were made with a calibrated GaAlAs diode placed close to the sample. AC current with a frequency of 80 Hz and a current density of 10 A/cm
2 was used. A lock-in technique was performed for the detection of the Hall voltage and the resistive voltage drop along the sample. The temperature variation of the Hall voltage was measured during a slow down-sweep in a magnetic field
B+0.7 T generated by an electromagnet, which was reversed for each datapoint to exclude any offset voltage."
Cautions: Evaluated Data
Digitized data were obtained from Figure 4 of the paper.
Hall Coefficient for Gd:123; [Gd-Ba-Sr-Cu-O]
| Phase () |
x of Ox (formula units) |
Temperature (K) |
Hall Coefficient (mm3 /C) |
| tetragonal |
7.00 |
84 |
-0.92 |
| tetragonal |
7.00 |
86 |
0.52 |
| tetragonal |
7.00 |
86 |
1.03 |
| tetragonal |
7.00 |
91 |
1.59 |
| tetragonal |
7.00 |
99 |
1.81 |
| tetragonal |
7.00 |
148 |
1.50 |
| tetragonal |
7.00 |
199 |
1.33 |
| tetragonal |
7.00 |
248 |
1.14 |
| tetragonal |
7.00 |
298 |
0.88 |
| orthorhom |
6.94 |
84 |
0.37 |
| orthorhom |
6.94 |
85 |
1.74 |
| orthorhom |
6.94 |
87 |
2.70 |
| orthorhom |
6.94 |
87 |
3.22 |
| orthorhom |
6.94 |
98 |
3.44 |
| orthorhom |
6.94 |
148 |
2.85 |
| orthorhom |
6.94 |
199 |
2.36 |
| orthorhom |
6.94 |
248 |
1.81 |
| orthorhom |
6.94 |
298 |
1.47 |
Measurement Method: Five-probe method
"The transport measurements were performed on thin, bar-shaped samples, which were cut from the ceramic pellets. Contacts were established in the usual five-probe geometry with Ag paste and gold wires. The measurements were carried out in a closed-cycle refrigerator. Temperature was controlled by a platinum resistor and precision temperature measurements were made with a calibrated GaAlAs diode placed close to the sample. AC current with a frequency of 80 Hz and a current density of 10 A/cm
2 was used. A lock-in technique was performed for the detection of the Hall voltage and the resistive voltage drop along the sample. The temperature variation of the Hall voltage was measured during a slow down-sweep in a magnetic field
B+0.7 T generated by an electromagnet, which was reversed for each datapoint to exclude any offset voltage."
Cautions: Evaluated Data
Digitized data were obtained from Figure 6 of the paper.
Magnetic Susceptibility for Gd:123; [Gd-Ba-Sr-Cu-O]
| Phase () |
x of Ox (formula units) |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| tetragonal |
7.00 |
10 |
-0.95 |
| tetragonal |
7.00 |
20 |
-0.91 |
| tetragonal |
7.00 |
50 |
-0.84 |
| tetragonal |
7.00 |
60 |
-0.77 |
| tetragonal |
7.00 |
70 |
-0.56 |
| tetragonal |
7.00 |
77 |
-0.31 |
| tetragonal |
7.00 |
80 |
-0.09 |
| tetragonal |
7.00 |
82 |
-0.06 |
| tetragonal |
7.00 |
88 |
-0.02 |
| tetragonal |
7.00 |
98 |
-0.02 |
| orthorhombic |
6.94 |
10 |
-0.95 |
| orthorhombic |
6.94 |
30 |
-0.95 |
| orthorhombic |
6.94 |
50 |
-0.94 |
| orthorhombic |
6.94 |
70 |
-0.94 |
| orthorhombic |
6.94 |
80 |
-0.88 |
| orthorhombic |
6.94 |
83 |
-0.74 |
| orthorhombic |
6.94 |
86 |
-0.26 |
| orthorhombic |
6.94 |
88 |
-0.03 |
| orthorhombic |
6.94 |
98 |
-0.03 |
Measurement Method: AC susceptibility
"The AC magnetic susceptibility measurements were performed with an AC susceptometer at a magnetic field of (1 Oe = 79.6 A/m) and a frequency of 680 Hz from a temperature of 10 K up to about 120 K."
Cautions: Evaluated Data
Digitized data were obtained from Figure 5 of the paper.
