A.F. Maiorova

Thermochemical characteristics of nonstoichiometric Ba2Cu3O5: II. Thermal transformations

Abstract Thermoanalysis (TG-DSC) of the pure compound Ba2Cu3O5+δ (023) has been carried out at oxygen pressures of 0.21 and 1 atm in the temperature range 25–970°C. It was shown that 5.5 823°C at 0.21 atm O2; > 890°C at 1 atm O2) appeared. The liquid phase transition took place at temperatures higher than 860°C (0.21 atm) and 910°C (1 atm).

Thermochemical characteristics of BaCuO2

Abstract Using simultaneous thermal analysis (TG + DSC), the heat capacity and non-stoichiometry of BaCuO 2+ x in O 2 atmosphere have been investigated. The results are formulated as 2.11 ± 0.02 > 2 + x > 2.00 ± 0.02 for 600°C t C p = 0.405 + 1.05 × 10 −4 t (J/g −1 K −1 ) was measured in the temperature range 40°C t

Thermal analysis of mercury superconductor HgBa2CuO4 + x and its precursor Ba2CuO3 + y☆

The superconducting compound HgBa2CuO4 + x and its precursor Ba2CuO3 + y have been studied in an oxygen atmosphere by TG-DTA in the temperature interval 20–1100°C. It was supposed that the succession of chemical processes taking place during the heating (20° min−1, 1 atm O2) of HgBa2Cu1.05O4.12 is as follows: It was supposed that the Ba2CuO3.23 compound during heating (1° min−1, 0.21 atm O2) and cooling (20° min−1, 0.21 atm O2) undergoes following stages:

Solid solution in the system BaCuO2CuOO2

The existence of an homogenity range of BaCu1 + yO2 + x in respect of copper was established by EMF measurement and DTA, and the nonstoichiometry index (xt) of oxygen versus temperature (t) was measured by TG in static dry oxygen. The values obtained for x and y were: 0≤y(±0.02)≤0.15 0.05 (1000°C) ≤ xt(pO2 = 1 atm, y = 0.15) ± 0.03 < 0.25 (450°C) significant attention was paid to phase and composition analysis of samples synthesized.