Material Specification for Hg:1223; [Hg(Pb)-Ba-Ca-Cu-O]
Process: Solid State Reaction
Notes: The authors cite H.M. Shao et al., Physica C, Vol. 232, 5 (1994), and summarize the procedure as follows. "Polycrystalline samples... were synthesized from analytical reagents of HgO, PbO, BaO, CaO and CuO powders by using encapsulation and short-time annealing techniques. ... Final mixtures with the stated compositions were pressed into pellets with rectangular dimension of 2 x 4 x 20 mm3. The obtained pellets were sealed together in a vacuum quartz tube (inner diameter of 7.0 mm, outer diameter of 11.0 mm and 80.0 mm length) which was in turn placed in a steel container to protect the sputtering of the quartz lining and mercury fragments due to some possible explosion. The whole system was then slowly heated, with heating speed of about 4 °C/min, to a temperature of 750-850 °C. The sample was maintained at this temperature for 3 h to 10 h, and finally cooled to 200 °C with the same speed as in the heating process. Eventually, the sample was cooled in furnace to room temperature. The second step of the synthesis was to carry out further heat treatment... Two types of samples could be obtained: (1) The as-prepared samples were subjected to a further heat treatment which was performed under 240 °C for 10 h. Throughout the whole period, oxygen or argon flow was applied. Then the samples were pulled out from the furnace and quenched to room temperature in a dry box. (2) The annealed samples were heat treated in the same manner as the as-prepared samples, but finally cooled in the furnace at room temperature."
Formula: Hg1-xPbxBa2Ca2Cu3Oy
Informal Name: Hg:1223
Chemical Family: Hg(Pb)-Ba-Ca-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for Hg:1223; [Hg(Pb)-Ba-Ca-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
|
Cell Parameters
| Annealing Temperature (°C) |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 23 |
296 |
3.8521 |
-- |
15.840 |
| 200 |
296 |
3.8561 |
-- |
15.869 |
| 300 |
296 |
3.8580 |
-- |
15.885 |
| 400 |
296 |
3.8525 |
-- |
15.864 |
| 450 |
296 |
3.8520 |
-- |
15.856 |
Measurement Method: X-ray diffraction
"The powder X-ray diffraction... technique was used with CuKα
1 radiation... Based on diffraction lines which appear in the diffraction pattern, the superconducting phase, i.e. Hg-1223, may be determined to be a tetragonal crystal..." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 6 of the paper.
Critical Temperature for Hg:1223; [Hg(Pb)-Ba-Ca-Cu-O]
| x of Pbx (formula units) |
y of Oy (formula units) |
Critical Temperature (K) |
| 0 |
8.22 |
110 |
| 0.1 |
8.25 |
118 |
| 0.2 |
8.30 |
125 |
| 0.3 |
8.35 |
130 |
| 0.4 |
8.40 |
120 |
| 0.5 |
8.45 |
103 |
Measurement Method: Four-probe method
"The post-annealed samples were characterized by means of the conventional four-point probe method to determine their critical temperatures." No additional measurement details were noted.
Cautions: Unevaluated Data
Magnetic Susceptibility for Hg:1223; [Hg(Pb)-Ba-Ca-Cu-O]
| Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| 91 |
-0.93 |
| 117 |
-0.92 |
| 128 |
-0.82 |
| 132 |
-0.69 |
| 136 |
-0.47 |
| 139 |
-0.19 |
| 143 |
-0.05 |
| 148 |
-0.01 |
| 156 |
-0.01 |
Measurement Method: Ac susceptibility
"The measurement was performed very carefully by using a frequency of 160 Hz and magnetic field amplitude of H
= 16 A/m (0.2 Oe). The temperature was recorded by a silicon diode thermometer which was well calibrated. The accuracy of this thermometer is ±0.1 K." No additional measurement details were noted.
Cautions: Unevaluated Data
Digitized data were obtained from Figure 2 of the paper.
