Material Specification for Ba:11; [Ba(K)-Bi-O]
Process: Solid State Reaction
Notes: "For successful and reproducible synthesis of BKBO, it must be emphasized that strictly anhydrous conditions be employed. ... We have had the greatest deal of success in preparing BKBO (x ≤0.5) from BaBiO3, KX, and Bi2O3 in stoichiometric quantities. BaBiO3 is simply prepared from Ba(NO3)2 and Bi2O3 that have been ground to powders and fired in gold crucibles (Pt is attacked) at 825 °C in air for 1 h followed by regrinding and reheating for 2-4 h. Here, X may be nitrate, superoxide, oxide, or if higher temperatures are used, carbonate. ...we typically ramp the temperature up from 350 °C to 415 °C over a period of one hour, hold at that temperature for two to four hours, and then ramp down to 200 °C in four to six hours. ... The material thus prepared yield microcrystalline porous pellets. In order to prepare higher density material, we have found it useful to melt the material. Melting the material is carried out in gold crucibles at temperatures in excess of 875 °C under Ar. By slow cooling of the melt through the freezing point and then cooling to room temperature followed by oxygenating... dense, highly faceted, large grained (0.25-0.5 mm) superconducting samples may be prepared."
Formula: Ba0.6K0.4BiO3
Informal Name: Ba:11
Chemical Family: Ba(K)-Bi-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Ba:11; [Ba(K)-Bi-O]
| Crystal System: | Cubic |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| x of Kx (formula units) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 0.30 |
296 |
4.2807 |
-- |
-- |
| 0.33 |
296 |
4.2746 |
-- |
-- |
| 0.36 |
296 |
4.2750 |
-- |
-- |
| 0.38 |
296 |
4.2741 |
-- |
-- |
| 0.40 |
296 |
4.2818 |
-- |
-- |
| 0.40 |
296 |
4.2729 |
-- |
-- |
| 0.40 |
296 |
4.2664 |
-- |
-- |
| 0.42 |
296 |
4.2684 |
-- |
-- |
| 0.42 |
296 |
4.2697 |
-- |
-- |
| 0.44 |
296 |
4.2688 |
-- |
-- |
| 0.47 |
296 |
4.2574 |
-- |
-- |
| 0.50 |
296 |
4.2550 |
-- |
-- |
Measurement Method: Unknown diffraction method
No measurement details were noted.
Cautions: Unevaluated Data
Digitized data were obtained from Figure 2 of the paper.
Critical Temperature for Ba:11; [Ba(K)-Bi-O]
| Critical Temperature (K) |
| 29 |
Measurement Method: Unknown susceptibility method
No measurement details were noted.
Cautions: Unevaluated Data
Magnetic Susceptibility for Ba:11; [Ba(K)-Bi-O]
| Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| 5.1 |
-0.97 |
| 7.2 |
-0.96 |
| 10.2 |
-0.95 |
| 14.1 |
-0.89 |
| 16.0 |
-0.82 |
| 18.1 |
-0.71 |
| 20.2 |
-0.52 |
| 20.1 |
-0.44 |
| 22.0 |
-0.15 |
| 24.1 |
-0.04 |
| 25.0 |
-0.02 |
| 26.4 |
-0.01 |
| 27.0 |
0.00 |
| 28.0 |
0.00 |
Measurement Method: Unknown susceptibility method
No measurement details were noted.
Cautions: Unevaluated Data
Digitized data were obtained from Figure 1 of the paper.
Specific Heat for Ba:11; [Ba(K)-Bi-O]
| Temperature (K) |
Specific Heat (J kg-1 K-1) |
| 2.0 |
0.000023 |
| 2.8 |
0.000070 |
| 3.5 |
0.00014 |
| 4.1 |
0.00021 |
| 7.1 |
0.0010 |
| 9.6 |
0.0021 |
| 10.0 |
0.0026 |
| 14.2 |
0.0063 |
| 18.1 |
0.012 |
| 19.2 |
0.014 |
| 20.1 |
0.016 |
| 21.1 |
0.018 |
| 22.3 |
0.020 |
| 26.7 |
0.030 |
| 29.7 |
0.037 |
| 30.5 |
0.041 |
| 32.0 |
0.044 |
| 33.4 |
0.050 |
| 34.9 |
0.055 |
| 35.5 |
0.058 |
Measurement Method: Specific heat method
"The technique used was a quasi-adiabatic thermal relaxation method that allows an accurate absolute determination of heat capacity but is limited in its ability to detect small relative changes due to experimental scatter which is typically on the order of a few percent." No additional measurement details were noted.
Cautions: Unevaluated Data
Digitized data were obtained from Figure 5 of the paper.
