Material Specification for Y:123; [Y-Ba-Cu-O]
Process: Solid State Reaction
Notes: "... the starting composition used in the present experiments has been fixed at Y:Ba:Cu=1:18:45....High purity Y2O3 (99.999%), CuO (99.999%) and BaCO3 (99.997%) were used as starting materials. These chemicals with a total mass of about 85 g were accurately weighed and mixed in a power mortar with agate components. About 70% of the mixed powder was pressed into 2.5 cm diameter pellets. Then the pellets, together with the rest of the powder, were packed into a 20 ml high form YSZ crucible with 38 mm top diameter, 25 mm bottom diameter and 35 mm height. The crucible was set into a muffle furnace... on a ceramic roll. This setup has allowed us, at the end of the crystal growth, to turn over the crucible using the quartz glass rod and to empty the flux onto the porous ceramic with no thermal shock to the crystals. The temperature of the furnace was controlled by a Eurothern model 818P programmable controller to the precision of ±0.2 °C and was well calibrated by a standard R-type thermocouple to the accuracy of ±2 °C... The crucible was first heated up to 870 °C and held there for 4 h to evaporate carbonates. Then the temperature was increased to 1010 °C, held for 4 h and cooled to 990 °C. After soaking at 990 °C for 8 h to 16 h, the crucible was slowly cooled at a rate of 0.3-0.8 °C/h to 950-970 °C. Then the flux was poured onto the porous ceramic using the quartz glass rod to overturn the crucible. Finally, the crucible was cooled to room temperature at the rate of 150 °C/h... To oxide the crystals, they were put on a piece of YBCO ceramic and set into a tube furnace. Under high purity oxygen flow, the crystals were first annealed at 860 °C for 48 h, slowly cooled at the rate of 18 °C/h to 450 °C and then annealed for 7 days."
Formula: YBa2Cu3O7-x
Informal Name: Y:123
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Single Crystal
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Y:123; [Y-Ba-Cu-O]
| Crystal System: | Orthorhombic |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 296 |
3.820 |
3.886 |
11.691 |
Measurement Method: X-ray diffraction
"Lattice parameters (were) measured by single crystal X-ray diffraction at room temperature..."
Cautions: Unevaluated Data
No measurement details were noted.
Critical Temperature for Y:123; [Y-Ba-Cu-O]
| Critical Temperature (K) |
| 93.1 |
Measurement Method: Four-probe method
"The a-b plane resistivity was measured at a frequency of 98 Hz by a standard four-probe direct method on a 0.06 mm thick crystal... The superconducting transition temperature, T
c, (was) taken as the zero resistivity temperature..."
Cautions: Evaluated Data
Surface Resistance for Y:123; [Y-Ba-Cu-O]
| Temperature (K) |
Surface Resistance (mΩ) |
| 80 |
0.012 |
| 81 |
0.015 |
| 82 |
0.014 |
| 83 |
0.017 |
| 84 |
0.019 |
| 85 |
0.021 |
| 86 |
0.025 |
| 87 |
0.029 |
| 88 |
0.037 |
| 89 |
0.048 |
| 90 |
0.077 |
| 91 |
0.13 |
| 92 |
0.33 |
| 92.5 |
1.9 |
| 93 |
43.0 |
| 95 |
64.0 |
Measurement Method: Surface resistance method
The authors cite D.A. Bonn et al., Rev. Sci. Instr., Vol. 62, 1819 (1991), and summarize the procedure as follows. "The surface resistance was measured at 1.7 GHz with a superconducting splitring resonator..."
Cautions: Evaluated Data
Digitized data were obtained from Figure 6 of the paper.
Specific Heat for Y:123; [Y-Ba-Cu-O]
| Temperature (K) |
Specific Heat (J kg-1 K-1) |
| 86 |
178 |
| 87 |
181 |
| 88 |
185 |
| 89 |
188 |
| 90 |
192 |
| 92 |
200 |
| 93 |
207 |
| 94 |
200 |
| 95 |
203 |
Measurement Method: Ac calorimetry
"The heat capacity of the crystals was measured using an AC calorimeter... the accuracy of the measurement is about 15% for the absolute heat capacity value..." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
