Material Specification for Hg:1223; [Hg-Ba-Ca-Cu-O]
Process: Solid State Reaction
Notes: "The Hg-1223 samples examined in this paper were synthesized directly from HgO, BaO, CaO, and CuO. BaO and BaO were obtained from the decomposition of BaCO3 and CaCO3 under vacuum at 950 °C; HgO and CuO were used as purchased (all starting chemicals were 99.99% purity or higher). Stoichiometric amounts of the starting oxides were intimately ground by hand in a glove bag under a nitrogen atmosphere. The samples were then pelletized, sealed in an evacuated quartz tube, and fired in a tube furnace. Since the unreacted samples readily absorb moisture and CO2, great care was used to minimize the exposure of the prefired material to air. The samples were then heated at a rate of 3 °C/min to 850 °C, held at 850 °C for 5 h, and then quenched to room temperature. ... To investigate the effect of oxygen concentration on superconducting and structural properties, samples were subjected to various annealing conditions. Samples A and C were obtained from a single synthesis batch which was divided into separate 2.5 g samples. Sample A was then annealed in flowing oxygen at 400 °C and sample C was reduced in flowing Ar at 500 °C. ... To produce sample B, a pellet of Hg-1223 was sealed in a quartz tube with an excess of liquid Hg and Cu2O, at a position separated from the sample, and held at 750 °C for 5 h. Hg and Cu2O were added to set the Hg and oxygen vapor pressure (60 and 10-4 bars, respectively), to values where Hg-1223 is stable but Ba2Cu3O5+δ is unstable."
Formula: HgBa2Ca2Cu3O8+x
Informal Name: Hg:1223
Chemical Family: Hg-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-Ba-Ca-Cu-O]
div class="table-responsive">
| Crystal System: | Tetragonal |
| Formula Units per Cell: | |
| Space Group: |
P4/mmm
|
Cell Parameters
| Sample Number () |
Occupancy () |
Temp
K
|
a
Å
|
b
Å
|
c
Å
|
| A |
--- |
296 |
3.84786(4) |
-- |
15.7782(3) |
| B |
--- |
296 |
3.85453(6) |
-- |
15.8252(4) |
| C |
--- |
296 |
3.85465(3) |
-- |
15.8251(2) |
Atomic Coordinates
| Sample Number () |
Occupancy () |
Atom |
Temp
K
|
a-axis |
b-axis |
c-axis |
| A |
0.95(2) |
Hg |
296 |
0 |
0 |
0 |
| A |
-- |
Ba |
296 |
0.5 |
0.5 |
0.1739(9) |
| A |
-- |
Ca |
296 |
0.5 |
0.5 |
0.3967(3) |
| A |
-- |
Cu(1) |
296 |
0 |
0 |
0.5 |
| A |
-- |
Cu(2) |
296 |
0 |
0 |
0.2987(2) |
| A |
-- |
O(1) |
296 |
0 |
0.5 |
0.5 |
| A |
-- |
O(2) |
296 |
0.5 |
0 |
0.3004(2) |
| A |
-- |
O(3) |
296 |
0 |
0 |
0.1250(2) |
| A |
0.18(2) |
O(4) |
296 |
0.5 |
0.5 |
0 |
| A |
0.09(2) |
O(5) |
296 |
0.5 |
0 |
0 |
| B |
0.90(2) |
Hg |
296 |
0 |
0 |
0 |
| B |
-- |
Ba |
296 |
0.5 |
0.5 |
0.1776(3) |
| B |
-- |
Ca |
296 |
0.5 |
0.5 |
0.3974(4) |
| B |
-- |
Cu(1) |
296 |
0 |
0 |
0.5 |
| B |
-- |
Cu(2) |
296 |
0 |
0 |
0.3004(2) |
| B |
-- |
O(1) |
296 |
0 |
0.5 |
0.5 |
| B |
-- |
O(2) |
296 |
0.5 |
0 |
0.3012(2) |
| B |
-- |
O(3) |
296 |
0 |
0 |
0.1244(3) |
| B |
0.13(2) |
O(4) |
296 |
0.5 |
0.5 |
0 |
| B |
0.09(2) |
O(5) |
296 |
0.5 |
0 |
0 |
| C |
0.95(1) |
Hg |
296 |
0 |
0 |
0 |
| C |
-- |
Ba |
296 |
0.5 |
0.5 |
0.1773(2) |
| C |
-- |
Ca |
296 |
0.5 |
0.5 |
0.3976(3) |
| C |
-- |
Cu(1) |
296 |
0 |
0 |
0.5 |
| C |
-- |
Cu(2) |
296 |
0 |
0 |
0.3003(2) |
| C |
-- |
O(1) |
296 |
0 |
0.5 |
0.5 |
| C |
-- |
O(2) |
296 |
0.5 |
0 |
0.3009(2) |
| C |
-- |
O(3) |
296 |
0 |
0 |
0.1243(2) |
| C |
0.10(2) |
O(4) |
296 |
0.5 |
0.5 |
0 |
| C |
0.08(2) |
O(5) |
296 |
0.5 |
0 |
0 |
Measurement Method: Neutron diffraction
"Neutron powder diffraction data on samples A and C were collected on the General Purpose Powder Diffractometer (GPPD). Sample B was run on the Special Environment Powder Diffractometer. ... The samples (about 2.5 g) were measured in the form of loose powders inside 6.35 mm (0.25 in) diameter thin-walled vanadium sample holders. ... The powder diffraction data were analyzed utilizing the IPNS time-of-flight Rietveld code. Only data from the high-resolution backscattering detector banks were used in the refinements."
Cautions: Evaluated Data
Magnetic Susceptibility for Hg:1223; [Hg-Ba-Ca-Cu-O]
| Sample Number () |
Temperature (K) |
Magnetic Susceptibility (arbitrary) |
| A |
70 |
-12.4 |
| A |
80 |
-12.3 |
| A |
90 |
-12.1 |
| A |
100 |
-11.8 |
| A |
111 |
-11.2 |
| A |
120 |
-10.4 |
| A |
131 |
-8.4 |
| A |
135 |
-4.0 |
| A |
136 |
0.0 |
| A |
140 |
0.0 |
| B |
70 |
-9.3 |
| B |
82 |
-8.6 |
| B |
93 |
-7.5 |
| B |
101 |
-6.4 |
| B |
104 |
-4.6 |
| B |
105 |
-2.7 |
| B |
106 |
-1.2 |
| B |
108 |
0.0 |
| B |
110 |
0.0 |
| C |
71 |
-9.4 |
| C |
84 |
-8.6 |
| C |
89 |
-7.9 |
| C |
91 |
-5.1 |
| C |
92 |
-2.4 |
| C |
93 |
-0.8 |
| C |
94 |
0.0 |
| C |
100 |
0.0 |
Measurement Method: AC susceptibility
"...ac susceptibility was measured on powdered samples in a (0.1 mT = 1 G), 100 Hz field using a Lake Shore Cryotronics model 7000 ac susceptometer." No additional measurement details were noted.
Cautions: Evaluated Data
Digitized data were obtained from Figure 3 of the paper.
