Material Specification for CaLa:123; [Ca-La(Ba)-Cu-O]
Process: Solid State Reaction
Notes: The authors cite D.M. de Leeuw et al., Physica C, Vol. 152, 126 (1988), and summarize the procedure as follows. "Samples were prepared using the mixed oxide route... the resulting material is isomorphic to tetragonal YBa2Cu3O6+x (x < 0.35) with the Ca ions at the Y site and the La and Ba ions located at the Ba site."
Formula: CaLaBaCu3O7
Informal Name: CaLa:123
Chemical Family: Ca-La(Ba)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:
Critical Temperature for CaLa:123; [Ca-La(Ba)-Cu-O]
| Pressure (GPa) |
Critical Temperature (K) |
| 1.83 |
78 |
| 3.15 |
81 |
| 6.91 |
81 |
| 8.15 |
79 |
| 12.45 |
82 |
| 19.48 |
81 |
| 30.53 |
85 |
| 38.87 |
87 |
Measurement Method: Four-probe method
The authors cite E.N. van Eenige et al., Physica C, Vol. 168, 482 (1990), and summarize the procedure as follows. "To determine T
c, four-point resistivity measurements were done on the 400 µm diameter samples, using an insulated gasket and four gold wires pressed onto the sample... To measure the very small resistances, a low frequency lock-in technique was used, which reverses the 1 mA measurement current every 0.25 s, thus also correcting for thermovoltages. The onset T
c... is determined from (the intersection of) the tangents on the resistivity curve in the normal state and halfway down the transition... To determine the upper critical field H
, resistance was measured as a function of temperature in external fields of 0 T, 1 T, 4 T and 10 T. For each applied field H the onset of the resistive transition, found at a temperature T, defines the upper critical field H
... The pressure dependence... is measured by means of a specially designed cryogenic diamond anvil cell which fits into the bore of a 12 T Thor-Cryogenic superconducting magnet together with an optical cryostat enabling optical access to the sample space. The diamonds are 16 sided and single bevelled with a culet diameter of 800 µm. Pressure is measured by the R1 ruby fluorescence."
Cautions: Evaluated Data
The quoted Tc values are onset values in zero magnetic field.
Critical Flux Density Hc2 for CaLa:123; [Ca-La(Ba)-Cu-O]
| Pressure (GPa) |
Crit.Mag.Flux Density Hc2 (T) |
| 1.83 |
98 |
| 3.15 |
96 |
| 6.91 |
116 |
| 8.15 |
125 |
| 12.45 |
111 |
| 19.48 |
97 |
| 30.53 |
100 |
| 38.87 |
78 |
Measurement Method: Four-probe method
The authors cite E.N. van Eenige et al., Physica C, Vol. 168, 482 (1990), and summarize the procedure as follows. "To determine T
c, four-point resistivity measurements were done on the 400 µm diameter samples, using an insulated gasket and four gold wires pressed onto the sample... To measure the very small resistances, a low frequency lock-in technique was used, which reverses the 1 mA measurement current every 0.25 s, thus also correcting for thermovoltages. The onset T
c... is determined from (the intersection of) the tangents on the resistivity curve in the normal state and halfway down the transition... To determine the upper critical field H
, resistance was measured as a function of temperature in external fields of 0 T, 1 T, 4 T and 10 T. For each applied field H the onset of the resistive transition, found at a temperature T, defines the upper critical field H
... The pressure dependence... is measured by means of a specially designed cryogenic diamond anvil cell which fits into the bore of a 12 T Thor-Cryogenic superconducting magnet together with an optical cryostat enabling optical access to the sample space. The diamonds are 16 sided and single bevelled with a culet diameter of 800 µm. Pressure is measured by the R1 ruby fluorescence."
Cautions: Evaluated Data
