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NIST High Temp. Superconducting Materials (HTS) Database:

NIST Standard Reference Database 62

Last Update to Data Content: 1996

DOI: https://doi.org/10.18434/T4KP8J

Bibliographic Information

Title: Structure, Doping and Superconductivity in HgBa2CaCu2O6+x
Author(s): P.G. Radaelli, J.L. Wagner, B.A. Hunter, M.A. Beno, G.S. Knapp, J.D. Jorgensen, and D.G. Hinks
Publication: Physica C Volume: 216 Issue: Not Available Year: 1993 Page(s): 29-35
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature, Magnetic Susceptibility

Materials and Properties

Hg:1212; [Hg-Ba-Ca-Cu-O]
Material Specification for Hg:1212; [Hg-Ba-Ca-Cu-O] Process: Solid State Reaction
Notes: "... we were successful in synthesizing samples containing more than 70% by volume of HgBa2CaCu2O6+δ by directly reacting BaO, CaO, CuO and HgO... BaO and CaO were obtained by decomposing BaCO3 and CaCO3 in a vacuum furnace at 950 °C overnight. Stoichiometric amounts of BaO, CaO, CuO and HgO were intimately ground in a glove bag under nitrogen atmosphere, using an agate mortar, and then pressed into pellets. Care was taken to minimize the exposure of the reactive prefired samples to air, in order to prevent the absorption of moisture and CO2. The pellets were then sealed in quartz tubes and slowly heated (1 to 2 °C/min) to 800 °C, held at 800 °C for 8 h, then cooled to room temperature... In order to investigate the effect of the oxygen content on the superconducting properties, two samples from a single synthesis batch were treated at 300 °C in flowing oxygen and at 600 °C in flowing argon (99.999% purity), respectively. After measuring the AC susceptibility and obtaining neutron powder diffraction data, the argon-reduced sample was re-oxygenated at 300 °C in flowing oxygen."
Formula: HgBa2CaCu2O6+x
Informal Name: Hg:1212
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:1212; [Hg-Ba-Ca-Cu-O]
Crystal System: Tetragonal
Formula Units per Cell:
Space Group: P4/mmm
Cell Parameters
Specimen Condition () Occupancy () Temp K a Å b Å c Å
Ar-reduced -- 296 3.8630(1) -- 12.6978(2)
Re-ox -- 296 3.8552(1) -- 12.6651(2)
Atomic Coordinates
Specimen Condition () Occupancy () Atom Temp K a-axis b-axis c-axis
Ar-reduced 0.96(1) Hg 296 0 0 0
Ar-reduced -- Ba 296 0.5 0.5 0.2243(2)
Ar-reduced -- Ca 296 0.5 0.5 0.5
Ar-reduced -- Cu 296 0 0 0.3772(2)
Ar-reduced -- O(1) 296 0 0.5 0.3765(2)
Ar-reduced -- O(2) 296 0 0 0.1548(2)
Ar-reduced 0.08(1) O(3) 296 0.5 0.5 0
Ar-reduced 0.00(1) O(4) 296 0 0.5 0
Re-ox 0.96(1) Hg 296 0 0 0
Re-ox -- Ba 296 0.5 0.5 0.2200(2)
Re-ox -- Ca 296 0.5 0.5 0.5
Re-ox -- Cu 296 0 0 0.3759(1)
Re-ox -- O(1) 296 0 0.5 0.3767(1)
Re-ox -- O(2) 296 0 0 0.1568(2)
Re-ox 0.22(1) O(3) 296 0.5 0.5 0
Re-ox 0.02(1) O(4) 296 0 0.5 0
Measurement Method: Neutron diffraction
"Neutron powder diffraction data were collected at room temperature... using the special environment powder diffractometer (SEPD) at Argonne's intense pulsed neutron source (IPNS). The samples, in the form of loose powder, were contained in thin-walled vanadium cans (6.35 mm = 0.25 inches) in diameter. The powder diffraction data were analyzed with the Rietveld technique, using the IPNS time-of-flight Rietveld code. Only data from the high-resolution back-scattering detector banks (2θ=145°) were used in the refinements."

Cautions: Evaluated Data
Critical Temperature for Hg:1212; [Hg-Ba-Ca-Cu-O]
Specimen Condition () Critical Temperature (K)
as-made 128
Ar-reduced 92
re-ox 126
Measurement Method: Ac susceptibility
"The AC susceptibility was measured on powdered samples in a (0.1 mT = 1 G) 100 Hz field, using a Lake Shore Cryotronics AC susceptometer."

Cautions: Evaluated Data
Magnetic Susceptibility for Hg:1212; [Hg-Ba-Ca-Cu-O]
Specimen Condition () Temperature (K) Magnetic Susceptibility (arbitrary)
Ar-reduced 8 -5.1
Ar-reduced 33 -4.6
Ar-reduced 63 -4.5
Ar-reduced 80 -4.0
Ar-reduced 90 -1.7
Ar-reduced 93 0
Ar-reduced 120 0
Ar-reduced 150 0
as-made 7 -12.4
as-made 40 -12.1
as-made 73 -11.3
as-made 107 -9.4
as-made 125 -5.0
as-made 129 0
as-made 150 0
Measurement Method: Ac susceptibility
"The AC susceptibility was measured on powdered samples in a (0.1 mT = 1 G) 100 Hz field, using a Lake Shore Cryotronics AC susceptometer."

Cautions: Evaluated Data
Digitized data were obtained from Figure 3 of the paper.