Applications of Thermal Analysis in the Field of High T sub C Superconductors

A variety of thermalanalytical techniques have proved very valuable in studying many of the crucial aspects relating to the preparation characterization and phase equilibria of the new high-T sub c superconducting oxides. Thermogravimetry has been extensively used to determine the critical oxygen content (x) of materials, e.g., Ba sub 2 YCu sub 3 O sub x , to map out the compositional fields as a function of P sub o sub 2 and temperature, and to study the degradation of these materials in various environments. Similarly, DTA and DSC have been useful in establishing the phase equilibria for the relevant systems. Thermodilatometry has provided not only values of the thermal expansion but also has found use in studying the orthohombic to tetragonal phase transition that takes place in Ba sub 2 YCu sub 3 O sub x.