Material Specification for Y:247; [Y-Ba-Cu-O]
Process: Solid State Reaction
Notes: "High-purity Y2O3 (99.999%), Fluka AG), BaCO3 (99.999%) and CuO powders (99.999%, both Alfa, Johnson Matthey) were fired in flowing oxygen at room pressure between 880 and 920 °C for one week, and then reground. This procedure was applied twice... The prereacted powders were cold pressed into 6 mm diameter pellets. Both 247 samples studied here, labeled Y4A6 and Y4A13T, were sintered under (2 MPa = 20 bar) O2 at 990 °C during two days... Switching off the induction furnace after the heat treatment resulted in a fast initial cooling rate (about 100 K/s). Sample Y4A13T was annealed under (9.1 MPa = 90 atm) O2 at 300 °C during 3 days."
Formula: YBa2Cu3.5O7.5+x
Informal Name: Y:247
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Y:247; [Y-Ba-Cu-O]
| Crystal System: | Orthorhombic |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| Sample Number () |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| Y4A6 |
296 |
3.8309(5) |
3.8765(2) |
50.593(3) |
| Y4A13T |
296 |
3.8319(6) |
3.8762(4) |
50.576(5) |
Measurement Method: X-ray diffraction
"The crystal structure was studied at ambient temperature by X-ray diffraction, using a Guinier camera with CuKα radiation. Silicon was added to the powdered samples as an internal standard (a = 5.4308 σ)... The lattice parameters were determined from least-squares fits using 25 indexed lines in the region 10°< 4θ <140°."
Cautions: Evaluated Data
Critical Temperature for Y:247; [Y-Ba-Cu-O]
| Sample Number () |
Critical Temperature (K) |
| Y4A6 |
92.3 |
| Y4A13T |
92.9 |
Measurement Method: Mutual inductance bridge
"The AC diamagnetism was recorded in a mutual inductance bridge working at 73 Hz, using an AC field amplitude of (7.96 A/m = 0.1 Oe
."
Cautions: Evaluated Data
Critical Current Density for Y:247; [Y-Ba-Cu-O]
| Sample Number () |
Magnetic Field (mA/m) |
Critical Current Density (kA/cm2) |
| Y4A6 |
0.16 |
24 |
| Y4A6 |
0.25 |
21 |
| Y4A6 |
0.36 |
18 |
| Y4A6 |
0.42 |
16 |
| Y4A6 |
0.84 |
4 |
| Y4A6 |
1.62 |
2 |
| Y4A6 |
2.42 |
2 |
| Y4A6 |
3.20 |
2 |
| Y4A6 |
3.98 |
1 |
Measurement Method: SQUID magnetometer
"We have measured the hysteresis of the DC magnetization at T=6 K, and estimated the critical current density versus the magnetic field using Bean's model for the critical state."
Cautions: Evaluated Data
Digitized data were obtained from Figure 11 of the paper.
Resistivity (normal state) for Y:247; [Y-Ba-Cu-O]
| Sample Number () |
Temperature (K) |
Resistivity (normal state) (mΩ·cm) |
| Y4A6 |
90.0 |
0.00 |
| Y4A6 |
92.4 |
0.01 |
| Y4A6 |
92.8 |
0.04 |
| Y4A6 |
93.4 |
0.11 |
| Y4A6 |
94.2 |
0.17 |
| Y4A6 |
95.0 |
0.19 |
| Y4A6 |
96.0 |
0.19 |
| Y4A6 |
98.0 |
0.19 |
Measurement Method: Four-probe method
"We used a standard four-point AC technique at low frequency (222 Hz) to measure the resistance as a function of temperature. Four gold contacts were sputtered onto the sample to improve the contact resistance. The current density was of the order of 10
-3 A/cm
2."
Cautions: Evaluated Data
Digitized data were obtained from Figure 3 of the paper.
Magnetic Susceptibility for Y:247; [Y-Ba-Cu-O]
| Sample Number () |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| Y4A6 |
85 |
-6.9 |
| Y4A6 |
90 |
-6.8 |
| Y4A6 |
91 |
-6.4 |
| Y4A6 |
92 |
-4.8 |
| Y4A6 |
93 |
-1.6 |
| Y4A6 |
94 |
-0.4 |
| Y4A6 |
95 |
0.0 |
| Y4A6 |
96 |
0.0 |
| Y4A13T |
85 |
-6.9 |
| Y4A13T |
90 |
-6.7 |
| Y4A13T |
91 |
-6.5 |
| Y4A13T |
92 |
-6.1 |
| Y4A13T |
93 |
-3.7 |
| Y4A13T |
94 |
-0.5 |
| Y4A13T |
95 |
0.0 |
| Y4A13T |
96 |
0.0 |
Measurement Method: Mutual inductance bridge
"The AC diamagnetism was recorded in a mutual inductance bridge working at 73 Hz, using an AC field amplitude of (7.96 A/m = 0.1 Oe
."
Cautions: Evaluated Data
Digitized data were obtained from Figure 4 of the paper.
Specific Heat for Y:247; [Y-Ba-Cu-O]
| Temperature (K) |
Specific Heat (J kg-1 K-1) |
| 2 |
0.022 |
| 5 |
0.13 |
| 10 |
0.83 |
| 25 |
15.4 |
| 50 |
78.5 |
| 75 |
148 |
| 100 |
207 |
| 125 |
257 |
| 150 |
297 |
| 175 |
331 |
| 200 |
351 |
| 225 |
380 |
| 250 |
397 |
| 275 |
412 |
| 298 |
423 |
| 300 |
424 |
| 325 |
433 |
Measurement Method: Relaxation technique
"The low-temperature specific heat was measured... using a relaxation technique. The sample mass was 41 mg. The accuracy was verified using copper and silver samples and was found to be 1% in zero field."
Cautions: Evaluated Data
Critical Field Strength Hc2 for Y:247; [Y-Ba-Cu-O]
| Temperature (K) |
Crit.Mag.Field Strength Hc2 (MA/m) |
| 90.2 |
4.4 |
| 90.4 |
3.9 |
| 90.5 |
3.2 |
| 90.9 |
2.3 |
| 91.3 |
1.6 |
| 91.6 |
0.8 |
| 91.9 |
0.2 |
| 92.1 |
0.1 |
Measurement Method: Mutual inductance bridge
"The AC diamagnetism was recorded in a mutual inductance bridge working at 73 Hz, using an AC field amplitude of (7.96 A/m = 0.1 Oe
."
Cautions: Evaluated Data
Digitized data were obtained from Figure 7 of the paper.
