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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: Pressure Dependence of Tc and H of YBa2Cu4O8
Author(s): J.J Scholtz, E.N. van Eenige, R.J. Wijngaarden, and R. Griessen
Publication: Physical Review B Volume: 45 Issue: 6 Year: 1992 Page(s): 3077-3082
Editor(s): Not Available
Publisher: American Physical Society
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature, Critical Flux Density Hc2

Materials and Properties

Y:124; [Y-Ba-Cu-O]
Material Specification for Y:124; [Y-Ba-Cu-O] Process: Solid State Reaction
Notes: "The sample... was synthesized under high oxygen pressure in a high-temperature two-chamber autoclave. A stoichiometric mixture of fine grained YBa2Cu3O7 and CuO resulting from the decomposition of oxalates was heated to 980 °C under 21 MPa oxygen for 30 h and then slowly cooled down at a rate of 5 °C/min."
Formula: YBa2Cu4O8
Informal Name: Y:124
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Crystallography for Y:124; [Y-Ba-Cu-O]
Crystal System: Orthorhombic
Formula Units per Cell:
Space Group:
Cell Parameters
Temp K a Å b Å c Å
296 3.8413 3.8708 27.240
Measurement Method: X-ray scattering

Cautions: Unevaluated Data
No measurement details were noted.
Critical Temperature for Y:124; [Y-Ba-Cu-O]
Pressure Cycle () Pressure (GPa) Critical Temperature (K)
1 Up 2.3 90
1 Up 3.4 101
1 Up 6.8 104
1 Up 10.7 105
1 Up 13.6 103
1 Up 17.3 101
1 Up 17.8 100
2 Up 1.2 86
2 Up 6.9 96
2 Up 7.0 97
2 Up 8.4 100
2 Up 10.3 102
2 Up 10.4 101
1 Down 0.7 85
1 Down 4.0 90
1 Down 3.9 91
1 Down 5.5 92
1 Down 5.5 93
1 Down 8.9 99
1 Down 11.7 101
1 Down 14.8 100
1 Down 15.8 101
1 Down 15.9 99
Measurement Method: Four-probe method
"Magnetic fields for the high-pressure experiments are generated by means of a 12-T Thor-Cryogenics superconducting magnet with a 53-mm room temperature bore and a field homogeneity of 1:105 in a 1-cm diameter sphere. Pressure is generated by means of a diamond anvil cell made of nonmagnetic stainless steel. A nonprepressurized stainless-steel gasket is used with an initial thickness of 100 µm. The gasket hole has a diameter of 300 µm. To measure pressure... ruby fluorescence method is used. The temperature of the sample can be changed continuously down to 10 K by means of a heat exchanger made of sintered copper, which is attached to the bottom of the diamond anvil cell. The resistance of the sample is measured by means of a four-point lock-in technique, which reverses the current every 0.25 s thus also correcting for thermovoltages. Electrical connections to the sample are made by six gold wires pressed onto the powdered sample..."

Cautions: Evaluated Data
"In this experiment we take as the critical temperature Tc the critical onset temperature, because we believe this to be close to the thermodynamic Tc."
Critical Flux Density Hc2 for Y:124; [Y-Ba-Cu-O]
Pressure (GPa) Temperature (K) Crit.Mag.Flux Density Hc2 (T)
0 78 10.0
0 79 7.9
0 79 7.0
0 80 4.0
0 81 3.0
0 81 2.0
0 82 0
2.3 84 10.0
2.3 87 4.0
2.3 88 1.0
2.3 90 0
13.7 88 10.0
13.7 91 7.9
13.7 93 5.8
13.7 95 4.0
13.7 99 2.0
13.7 103 0
3.4 93 10.0
3.4 97 4.0
3.4 100 1.0
3.4 101 0
Measurement Method: Four-probe method
"Magnetic fields for the high-pressure experiments are generated by means of a 12-T Thor-Cryogenics superconducting magnet with a 53-mm room temperature bore and a field homogeneity of 1:105 in a 1-cm diameter sphere. Pressure is generated by means of a diamond anvil cell made of nonmagnetic stainless steel. A nonprepressurized stainless-steel gasket is used with an initial thickness of 100 µm. The gasket hole has a diameter of 300 µm. To measure pressure... ruby fluorescence method is used. The temperature of the sample can be changed continuously down to 10 K by means of a heat exchanger made of sintered copper, which is attached to the bottom of the diamond anvil cell. The resistance of the sample is measured by means of a four-point lock-in technique, which reverses the current every 0.25 s thus also correcting for thermovoltages. Electrical connections to the sample are made by six gold wires pressed onto the powdered sample..."

Cautions: Evaluated Data
Digitized data were obtained from Figure 4 of the paper.