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: Structural Changes of Superconducting YBa2Cu4O8 under High Pressure
Author(s): Y. Yamada, J.D. Jorgensen, S. Pei, P. Lightfoot, Y. Kodama, T. Matsumoto, and F. Izumi
Publication: Physica C Volume: 173 Issue: Not Available Year: 1991 Page(s): 185-194
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature

Materials and Properties

Y:124; [Y-Ba-Cu-O]
Material Specification for Y:124; [Y-Ba-Cu-O] Process: Solid State Reaction
Notes: "... YBa2Cu4O8 was synthesized by a high-oxygen-pressure technique. Starting materials Y2O3, BaCO3 and CuO were mixed thoroughly and the mixture was calcined twice at 900 °C for 12 h in flowing oxygen with intermediate grinding. At this stage, the calcined powder... was pressed into a pellet and then reacted in an Ar(80%)+O2(20%) gas at 100 MPa and 1010 °C for 6 h."
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: 2
Space Group: Ammm
Cell Parameters
Pressure (GPa) Temp K a Å b Å c Å
0 296 3.84050(6) 3.87105(8) 27.2319(6)
0.138 296 3.83860(6) 3.87028(8) 27.2153(6)
0.276 296 3.83702(6) 3.86954(8) 27.2005(6)
0.455 296 3.83494(6) 3.86843(8) 27.1809(6)
0.632 296 3.83305(6) 3.86753(9) 27.1628(7)
Atomic Coordinates
Pressure (GPa) Atom Temp K a-axis b-axis c-axis
0 Y 296 0.5 0.5 0
0 Ba 296 0.5 0.5 0.1348(1)
0 Cu(1) 296 0 0 0.21328(6)
0 Cu(2) 296 0 0 0.06153(7)
0 O(1) 296 0 0 0.14527(8)
0 O(2) 296 0.5 0 0.05262(8)
0 O(3) 296 0 0.5 0.05240(9)
0 O(4) 296 0 0.5 0.21802(9)
0.138 Y 296 0.5 0.5 0
0.138 Ba 296 0.5 0.5 0.1349(1)
0.138 Cu(1) 296 0 0 0.21328(7)
0.138 Cu(2) 296 0 0 0.06157(7)
0.138 O(1) 296 0 0 0.14537(9)
0.138 O(2) 296 0.5 0 0.05251(9)
0.138 O(3) 296 0 0.5 0.0524(1)
0.138 O(4) 296 0 0.5 0.2179(1)
0.276 Y 296 0.5 0.5 0
0.276 Ba 296 0.5 0.5 0.1349(1)
0.276 Cu(1) 296 0 0 0.21331(7)
0.276 Cu(2) 296 0 0 0.06157(7)
0.276 O(1) 296 0 0 0.14533(9)
0.276 O(2) 296 0.5 0 0.05269(9)
0.276 O(3) 296 0 0.5 0.0522(1)
0.276 O(4) 296 0 0.5 0.2179(1)
0.455 Y 296 0.5 0.5 0
0.455 Ba 296 0.5 0.5 0.1349(1)
0.455 Cu(1) 296 0 0 0.21327(7)
0.455 Cu(2) 296 0 0 0.06165(7)
0.455 O(1) 296 0 0 0.14526(9)
0.455 O(2) 296 0.5 0 0.05275(9)
0.455 O(3) 296 0 0.5 0.0525(1)
0.455 O(4) 296 0 0.5 0.2178(1)
0.632 Y 296 0.5 0.5 0
0.632 Ba 296 0.5 0.5 0.1350(1)
0.632 Cu(1) 296 0 0 0.21332(7)
0.632 Cu(2) 296 0 0 0.06164(7)
0.632 O(1) 296 0 0 0.14514(9)
0.632 O(2) 296 0.5 0 0.05269(9)
0.632 O(3) 296 0 0.5 0.0525(1)
0.632 O(4) 296 0 0.5 0.2178(1)
Measurement Method: Neutron powder difffraction
"The authors cite J.D. Jorgensen et al., Physica C, Vol. 171, 93 (1990), and summarize the procedure as follows. "TOF neutron powder diffraction data of... were measured at five different pressures up to 0.632 GPa at room temperature on the Special Environment Powder Diffractomer... at Argonne's Intense Pulsed Neutron Source... data were collected using the fixed-angle time-of-flight (TOF) method with the sample in an aluminum pressure cell using helium gas as the pressure transmitting medium. The resulting data were analyzed using a Rietveld refinement program with multi-phase capability..."

Cautions: Evaluated Data
Critical Temperature for Y:124; [Y-Ba-Cu-O]
dTc/dP (K/GPa) Critical Temperature (K)
5.5 76
Measurement Method: Electrical resistance
"The pressure dependence of Tc... was determined by resistivity measurements." No additional measurement details were noted.

Cautions: Unevaluated Data