First observation of the specific heat jump at Tc in the Nd1.85Ce0.15CuO4−δ electron doped high Tc superconductor

Abstract We report the first observation of a specific heat anomaly at the superconducting transition temperature of high quality Nd 1.85 Ce 0.15 CuO 4−δ ceramics with Tc ≅ 25 K. The amplitude of the jump ΔC is weak, ΔC/T c ≅ 6.5 ± 0.5 mJ/mole. K 2 , but consistent with previous magnetic measurements and with earlier determination of thermodynamic field. Application of a magnetic field H results in a broadening of the Cp anomaly while the onset temperature remains field independant.