Material Specification for Y:123; [Y-Ba-Cu-O]
Process: Solid State Reaction
Notes: The authors cite T. Wolf et al., Physica C, Vol. 153-155, 351 (1988), and summarize the procedure as follows. "The... sample has been prepared by solid-state reaction of a mixed powder of Y2O3, BaCO3, and CuO. The stoichiometric mixture was cold pressed and calcined according to the direct preparation method... with a maximum temperature of 950 °C. The oxygen-content has been estimated from lattice parameters and Tc to be x = 6.93 ± 0.05, the density of the pellet being about 90%. All investigated samples came from this pellet by cutting off little bars with the size 1.2 x 1.2 x 7mm3. Each of these bars had to undergo an individual adjustment of the oxygen content by annealing it in air at a constant temperature between 400 °C and 700 °C for 24 h followed by a rapid quench in liquid N2... the bars were stored after the quench for several days at room temperature. The oxygen content of the bars has been determined by the weight-change caused by the oxygen adjustment. The accuracy of this method was estimated to be ±0.02... All oxygen contents... are related to the pellet... which gives an additive uncertainty in the oxygen content."
Formula: YBa2Cu3Ox
Informal Name: Y:123
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:
Critical Temperature for Y:123; [Y-Ba-Cu-O]
| x of Ox (formula units) |
Pressure (GPa) |
Critical Temperature (K) |
| 6.59 |
0.0 |
61.2 |
| 6.59 |
0.2 |
62.1 |
| 6.59 |
0.3 |
62.4 |
| 6.59 |
0.4 |
62.8 |
| 6.59 |
0.5 |
63.2 |
| 6.59 |
0.6 |
63.6 |
| 6.59 |
0.7 |
64.0 |
| 6.73 |
0.0 |
75.0 |
| 6.73 |
0.18 |
76.0 |
| 6.73 |
0.37 |
77.1 |
| 6.73 |
0.56 |
78.3 |
| 6.73 |
0.74 |
79.5 |
| 6.87 |
0.0 |
90.1 |
| 6.87 |
0.3 |
91.1 |
| 6.87 |
0.5 |
91.6 |
| 6.87 |
0.7 |
92.0 |
| 6.93 |
0.0 |
92.4 |
| 6.93 |
0.3 |
92.6 |
| 6.93 |
0.4 |
92.7 |
| 6.93 |
0.6 |
92.7 |
| 6.93 |
0.7 |
92.7 |
Measurement Method: Ac susceptibility
"In our experimental setup He gas is pressurized in a two step pressure-generation system consisting of a 0.15 GPa membrane compressor and an oil-driven 1 GPa, 1:16 pressure-amplifier. This pressure generator is connected to a CuBe pressure cell, which encloses the sample and a coil system consisting of a primary coil and two oppositely wound pick-up coils. The pick-up coils are connected to a two-channel lock-in amplifier. The primary coil is driven by a constant-current oscillator to ensure a constant field amplitude. For pressure determination we use a calibrated manganin coil at room temperature, which allows an accuracy in pressure determination of ±0.005 GPa to be achieved. The high-pressure cell is enclosed in a gas-flow cryostat. The temperature of this cryostat is adjustable between 15 and 320 K by controlling the He flow and the power of an electrical heater. The temperature is measured by calibrated Ge- and Pt-thermometers placed in bores of the pressure cell... An experimental cycle at a chosen pressure included the cooling of the sample well below T
c and heating at less than 5 mK/s to a temperature approximately 30 K above T
c. At that temperature all pressure changes were applied. During the cycles the real-part... the imaginary-part... He-pressure and temperature were recorded every 60 mK. An AC-field amplitude of 20 Am
-1 (0.25 Oe) and a frequency of 113 Hz were used. The first cycle of the investigation of a sample was performed at ambient pressure. Then the maximum pressure was applied, with a subsequent lowering of the pressure after each cycle. When ambient pressure was reached again, the susceptibility was remeasured, to ensure that the pressure-application caused no irreversibilities or damaging of the sample."
Cautions: Evaluated Data
Digitized data were obtained from Figure 3 of the paper.
