Material Specification for TlHg:2142; [Tl-Hg-Ba-Cu-O]
Process: Solid State Reaction
Notes: "The... cuprate was prepared by solid state reaction from the oxides BaO2, CuO, HgO and Tl2O3. The powders were mixed in an agate mortar, placed in an alumina crucible and sealed in an evacuated quartz ampoule. The mixture was heated progressively for 8 h to reach 800 °C and was then slowly cooled for 10 h down to 400 °C; it was finally furnace cooled down to room temperature... For the above conditions of synthesis, a nearly pure phase was obtained... Two main impurities have been observed by X-ray diffraction, BaCO3 and an unknown phase... the amount of these impurities can be estimated to be less than about 5%. Besides these two phases, traces of... HgBa2CuO4+δ, were also detected by electron microscopy, nevertheless, their presence cannot affect the physical properties since they are very rarely observed and can be estimated as less than 1% of the sample."
Formula: Tl2HgBa4Cu2O10+x
Informal Name: TlHg:2142
Chemical Family: Tl-Hg-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Crystallography for TlHg:2142; [Tl-Hg-Ba-Cu-O]
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
I4/mmm
|
Cell Parameters
|
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| 296 |
3.8584(1) |
-- |
42.2031(9) |
Atomic Coordinates
| Atom |
Temp
K
|
a-axis |
b-axis |
c-axis |
| Hg |
296 |
0 |
0 |
0 |
| Tl |
296 |
0 |
0 |
0.2240(1) |
| Cu |
296 |
0 |
0 |
0.1134(4) |
| Ba(1) |
296 |
0.5 |
0.5 |
0.0673(2) |
| Ba(2) |
296 |
0.5 |
0.5 |
0.1598(1) |
| O(1) |
296 |
0 |
0 |
0.050(1) |
| O(2) |
296 |
0.5 |
0 |
0.114(1) |
| O(3) |
296 |
0 |
0 |
0.180(1) |
| O(4) |
296 |
0.5 |
0.5 |
0.229(1) |
Measurement Method: X-ray diffraction
"X-ray powder data for structure determination were collected on a Seifert diffractometer equipped with a primary monochromator (CuKα
1 radiation) over an angular range of 2° to 100° with a step of 0.015° (2θ). The unit cell and crystallographic parameters were refined with the program DBW3.2."
Cautions: Evaluated Data
Critical Temperature for TlHg:2142; [Tl-Hg-Ba-Cu-O]
| Critical Temperature (K) |
| 50 |
Measurement Method: SQUID magnetometer
"The superconducting properties were investigated with a DC SQUID magnetometer with a field of (1 mT = 10 G) applied after the sample was zero-field cooled. No demagnetization corrections were made... (The sample was annealed) at T=220 °C in an Ar/H
2 (90%/10%) flow."
Cautions: Evaluated Data
Magnetic Susceptibility for TlHg:2142; [Tl-Hg-Ba-Cu-O]
| Annealing Time (min) |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| 15 |
10 |
-0.119 |
| 15 |
20 |
-0.043 |
| 15 |
30 |
-0.011 |
| 15 |
40 |
-0.004 |
| 15 |
50 |
0.00 |
| 30 |
10 |
-0.139 |
| 30 |
20 |
-0.099 |
| 30 |
30 |
-0.045 |
| 30 |
40 |
-0.004 |
| 30 |
50 |
0.00 |
| 45 |
10 |
-0.103 |
| 45 |
20 |
-0.085 |
| 45 |
30 |
-0.054 |
| 45 |
40 |
-0.011 |
| 45 |
50 |
0.00 |
| 60 |
10 |
-0.040 |
| 60 |
20 |
-0.036 |
| 60 |
30 |
-0.025 |
| 60 |
40 |
-0.004 |
| 60 |
50 |
0.00 |
Measurement Method: SQUID magnetometer
"The superconducting properties were investigated with a DC SQUID magnetometer with a field of (1 mT = 10 G) applied after the sample was zero-field cooled. No demagnetization corrections were made... (The sample was annealed) at T=220 °C in an Ar/H
2 (90%/10%) flow."
Cautions: Evaluated Data
Digitized data were obtained from Figure 5 of the paper.
