Material Specification for Y:123; [Y-Ba-Cu(Al)-O]
Process: Solid State Reaction
Notes: "The starting materials used were Y2O3 (Molycorp 99.99%), BaCO3 (Alfa, technical grade), CuO (Alfa, ACS grade), and Al2O3 (Baikowski, high-purity grade), YBa2Cu3O7-δ powder was synthesized by the solid-state reaction method. Appropriate quantities of the powders were slurry mixed in acetone using a mortar and pestle, oven dried at (about) 110 °C for 2 h, and calcined at (about) 920 °C for 16-18 h in air in an alumina crucible. The mixture was cooled slowly, pulverized, and recalcined 16-18 h at 920 °C. The cycle of calcining, cooling and grinding was repeated two more times resulting in a dark black powder. A master composition containing aluminium, YBa2Cu2Al1Oz, was synthesized in a similar manner. Aluminium-doped powders... were prepared by mixing calculated amounts of YBa2Cu3O7-δ and YBa2Cu2Al1Oz powders with mortar and pestle, calcining for 16-18 h at (about) 920 °C in air in alumina crucibles, and then furnace cooling to room temperature. The resulting mixtures were reground to fine powders, uniaxially dry-pressed into (about) 2.5 x 0.5 x 0.7 cm3 rectangular bars, and cold isostatically pressed at (about 414 MPa = 60000 p.s.i)... The bars were heated at 5 °C/min to 945 °C, sintered for 10 h, cooled at (about) 3 °C/min to 450 °C and held for 10 h, and finally furnace cooled to room temperature. The entire sintering and annealing cycle was carried out in flowing oxygen."
Formula: YBa2Cu3-xAlxOy
Informal Name: Y:123
Chemical Family: Y-Ba-Cu(Al)-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Y:123; [Y-Ba-Cu(Al)-O]
| Crystal System: | Orthorhombic |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| x of Alx (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 0.0 |
296 |
3.827 |
3.885 |
11.679 |
| 0.01 |
296 |
3.824 |
3.887 |
11.670 |
| 0.02 |
296 |
3.837 |
3.892 |
11.680 |
| 0.05 |
296 |
3.828 |
3.880 |
11.660 |
| 0.08 |
296 |
3.839 |
3.880 |
11.690 |
| 0.10 |
296 |
3.833 |
3.862 |
11.660 |
| 0.12 |
296 |
3.837 |
3.882 |
11.673 |
| 0.15 |
296 |
3.852 |
3.869 |
11.676 |
| 0.20 |
296 |
3.829 |
3.877 |
11.670 |
| 0.25 |
296 |
3.860 |
3.880 |
11.640 |
Measurement Method: X-ray diffraction
"A part of each sintered bar was ground to powder. Powder XRD patterns were recorded in the 2ϑ range 10°-90° at room temperature using a step-scan procedure (0.03°/2θ step, count time 0.4s) on a Philips ADP-3600 automated diffractometer equipped with a crystal monochromator employing CuK
α radiation."
Cautions: Evaluated Data
Critical Temperature for Y:123; [Y-Ba-Cu(Al)-O]
| x of Alx (formula units) |
ΔTc (10%-90%) (K) |
Tc(onset) (K) |
Critical Temperature (K) |
| 0.0 |
1.4 |
91.0 |
89.5 |
| 0.01 |
1.8 |
91.0 |
89.5 |
| 0.02 |
2.0 |
91.2 |
88.7 |
| 0.05 |
4.0 |
90.7 |
88.2 |
| 0.08 |
4.1 |
90.8 |
86.2 |
| 0.10 |
5.1 |
90.2 |
84.3 |
| 0.12 |
8.6 |
90.2 |
80.2 |
| 0.15 |
16 |
93.2 |
73.9 |
| 0.20 |
14 |
91.3 |
73.0 |
| 0.25 |
20.4 |
91.0 |
65.8 |
Measurement Method: Four-probe method
"Electrical resistivity measurements as a function of temperature were performed in the standard four-probe configuration. Silver paint was used to attach the leads, and the current density used was (about) 0.1 A cm
-2."
Cautions: Evaluated Data
