ABSTRACT
The discovery of superconductivity in the thallium barium calcium copper oxide (TBCCO) system generated intense interest and led to numerous structural studies and measurements of physical properties on these compounds. This chapter discusses brief description of the information obtained from specific-heat measurements on conventional superconductors, and a summary of the measurements on YBCO and their interpretation. Furthermore, analysis of the shape of the anomaly is always complicated by uncertainty in the subtraction of the background or lattice specific heat. The early specific-heat measurements on YBCO provided evidence of a bulk superconducting transition near 90 K, but the observed anomalies were relatively broad, with heights considerably lower than those observed in later experiments. The chapter discusses better specific-heat measurements on better samples, especially single crystals, should help to remove some of the ambiguities in the data.
