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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: Hall-Effect Measurements of HgBa2CaCu2O6+δ
Author(s): J.M. Harris, H. Wu, N.P. Ong, R.L. Meng, and C.W. Chu
Publication: Physical Review B Volume: 50 Issue: 5 Year: 1994 Page(s): 3246-3249
Editor(s): Not Available
Publisher: American Physical Society
Language: English
Notes: Not Available
Keywords: Material Specification, Critical Temperature, Resistivity (normal state), Hall Coefficient

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: The authors cite R.L. Meng et al., Physica C, Vol. 216, 21 (1993), and summarize the procedure as follows. "Hg-1212 is a member of the homologous series HgBa2Can-1CunO2n+2+δ with n=2, indicating two tightly coupled CuO2 planes per unit cell. ... The sample purity is 85% as determined by x-ray diffraction, neutron-diffraction, and magnetization measurements. Impurities consist of CaHgO2, BaCuO2, and Ba2Cu3O5.9. ... We annealed our samples at 300°C in one atmosphere of oxygen, a procedure that has been found to produce samples with close to optimal doping. ... The samples were cut into bars 2 mm x 1 mm x 175 µm and then mechanically polished, taking care to minimize the exposure time to atmosphere moisture. Contact pads were made by sputtering a Ag film or applying Ag epoxy. Having a freshly polished surface was important to producing low-resistance contacts (0.5-5 Ω) with low annealing temperatures (300 °C or less) and annealing times as short as 30 min."
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:

Critical Temperature for Hg:1212; [Hg-Ba-Ca-Cu-O]
Transition Width, ΔTc (K) Critical Temperature (K)
4 ± 1 122 ± 2
Measurement Method: Electrical transport methods
"Hall-effect and resistivity measurements were carried out in a 14 T superconducting magnet using two lock-in amplifiers synchronized at 16 Hz with J about 0.5 A/cm2. ... We reversed the magnetic field at each temperature by rotating the sample 180° to cancel the lead misalignment. The sample was carefully isolated from the liquid-helium bath using 15 layers of aluminized mylar so temperatures to 550 K could be reached. ... Each of the points above 300 K is the average of several readings."

Cautions: Evaluated Data
Resistivity (normal state) for Hg:1212; [Hg-Ba-Ca-Cu-O]
Annealing Time (h) Temperature (K) Resistivity (normal state) (mΩ·cm)
14 121 0
14 122 13
14 120 29
14 148 41
14 194 52
14 244 62
14 293 69
14 343 76
14 393 81
1.5 121 0
1.5 122 12
1.5 128 15
1.5 147 17
1.5 197 22
1.5 247 26
1.5 297 30
1.5 344 33
1.5 394 37
<1 114 0
<1 128 11
<1 147 14
<1 197 19
<1 247 23
<1 297 27
<1 316 29
Measurement Method: Electrical transport methods
"Hall-effect and resistivity measurements were carried out in a 14 T superconducting magnet using two lock-in amplifiers synchronized at 16 Hz with J about 0.5 A/cm2. ... We reversed the magnetic field at each temperature by rotating the sample 180° to cancel the lead misalignment. The sample was carefully isolated from the liquid-helium bath using 15 layers of aluminized mylar so temperatures to 550 K could be reached. ... Each of the points above 300 K is the average of several readings."

Cautions: Evaluated Data
Digitized data were obtained from Figure 1 of the paper.
Hall Coefficient for Hg:1212; [Hg-Ba-Ca-Cu-O]
Temperature (K) Hall Coefficient (mm3 /C)
125 2.4
126 3.5
127 4.7
130 4.8
137 5.0
148 4.8
155 4.7
166 4.5
217 3.6
246 3.1
285 2.7
317 2.4
356 2.1
409 1.8
420 1.8
451 1.7
469 1.7
Measurement Method: Electrical transport methods
"Hall-effect and resistivity measurements were carried out in a 14 T superconducting magnet using two lock-in amplifiers synchronized at 16 Hz with J about 0.5 A/cm2. ... We reversed the magnetic field at each temperature by rotating the sample 180° to cancel the lead misalignment. The sample was carefully isolated from the liquid-helium bath using 15 layers of aluminized mylar so temperatures to 550 K could be reached. ... Each of the points above 300 K is the average of several readings."

Cautions: Evaluated Data
"The temperature dependence of the Hall coefficient... for samples A and B... is the same for both samples in spite of their different resistivities." Digitized data were obtained from Figure 2 of the paper.