Estimation and revision of some thermodynamic data in the YBaCuO system. Part 3. Heat capacities

Abstract

By analysing the literature data for YBa 2Cu 3O 7 (123-O 7), YBa 2Cu 3O 6 (123-O 6), YBa 2Cu 4O 8 (124-O 8), YBa 2Cu 3.5O 7.5 (123.5-O 7.5), Y 2BaCuO 5 (211), BaCuO 2 (011), Y 2Cu 2O 5 (202), YCuO 2 (101), Y 2BaO 4 (210), Y 4Ba 3O 9 (430) and BaCu 2O 2 (012), the basic values of C ⊖ p (298) and the corrected temperature dependences of the heat capacity are suggested. It is shown that it is preferable to use the method of addition of the heat capacities of the simple oxides constituting the complex compounds (the method of Neumann-Kopp) for the calculation of the temperature dependences of the heat capacities of the compounds. In addition, the C p = f( T) dependences were also calculated for Y 2Ba 2O 5 (220), Ba 2CuO 3 (021). Ba 3CuO 4 (031), YBa 4Cu 3O 8.5 (143-O 8.5) and YBa 2Cu 5O 9 (125-O 9).