Material Specification for Y:124; [Y-Ba-Cu-O]
Process: Solid State Reaction
Notes: "Y-124 was prepared by mixing Y2O3, Ba(NO3)2 and CuO in required proportion and about 0.3 mole fraction of NaNO3 was added to enchance the reaction rate. The mixture was prereacted in air at 700 °C for 40 min. The prereacted mixture was ground, pelletised and annealed in flowing oxygen at 820 °C for 3 days, with an intermittent grinding and pelletising."
Formula: YBa2Cu4O8
Informal Name: Y:124
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:124; [Y-Ba-Cu-O]
| Crystal System: | Orthorhombic |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 296 |
3.8337 |
3.8523 |
27.1734 |
Measurement Method: X-ray diffraction
"... the compound gave a clean X-ray diffraction pattern where all the lines can be indexed based on the a-centered orthorhombic cell..." No additional measurement details were noted.
Cautions: Unevaluated Data
Thermoelectric Power for Y:124; [Y-Ba-Cu-O]
| Pressure (GPA) |
Thermoelectric Power (µV/K) |
| 0.12 |
15.4 |
| 0.36 |
15.3 |
| 0.66 |
13.9 |
| 1.56 |
12.4 |
| 2.11 |
11.9 |
| 2.41 |
11.3 |
| 3.61 |
8.6 |
| 4.27 |
7.0 |
| 5.23 |
6.0 |
| 5.35 |
5.2 |
| 5.83 |
4.8 |
| 6.19 |
5.1 |
| 6.68 |
3.9 |
| 6.98 |
4.2 |
| 7.40 |
3.9 |
| 7.58 |
4.1 |
Measurement Method: High-pressure thermopower
"The high pressure experiments were done with tungsten carbide anvils with binding rings. Talc was used as a pressure transmitting medium... a piece of the pellet of Y-124 measuring approximately 4x1 mm
2 and 0.4 mm thick was set in a pyrophyllite gasket (all the gaskets used in this study had an outside diameter of 12.5 mm and inside diameter of 5 mm) with talc and epoxy mixture. After allowing the epoxy to set the gasket-sample assembly was thinned down to 0.27 mm by working both sides on a 600 grade emery paper and this gasket formed the central gasket in the stack of three gaskets. The lower gasket with a talc disc at the center contains the heater wire and two thermojunctions (Chromel-alumel). The top gasket along with the talc disc insulates the sample from the top anvil. By passing a suitable current through the heater wire a temperature gradient was set up across the sample and the TEP was calculated by measuring the voltage drops across the top chromels and the two alumels."
Cautions: Evaluated Data
Digitized data were obtained from Figure 2 of the paper.
No measurement details were noted.
