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 T
c... was determined by resistivity measurements." No additional measurement details were noted.
Cautions: Unevaluated Data