Heat capacity of the high-temperature superconductor ${\mathrm{Ba}}_2$Dy${\mathrm{Cu}}_3$${\mathrm{O}}_7$

The high-temperature superconductor ${\mathrm{Ba}}_2$Dy${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ has been prepared, and characterized by electrical resistivity and dc magnetic susceptibility measurements. The heat capacity has been measured by an adiabatic calorimeter between 14 and 300 K. A typical second-order type of anomaly is observed due to the superconducting phase transition at 92.5 K. The heat-capacity jump at the transition point is obtained as 3.7 × J${\mathrm{K}}^{-1\mathrm{}}$ ${\mathrm{mol}}^{-1\mathrm{}}$ which leads to the electronic heat-capacity coefficient $\gamma$ of 28 mJ ${\mathrm{K}}^{-2\mathrm{}}$ ${\mathrm{mol}}^{-1\mathrm{}}$ in the weak-coupling limit of the Bardeen-Cooper-Schrieffer theory.