Specific heat of the electronic superconductor Pr1.85Ce0.15CuO4

We have investigated the specific heat of the ceramic Pr1.85Ce0.15CuO4 in the temperature range 2–800K in magnetic fields up to 8 T. We have determined the magnitude of the specific-heat discontinuity at the superconducting transition ΔC/Tc and estimate the coefficient of the electronic specific heat. In the temperature interval 5–800K we have separated out the phonon contribution to the specific heat, determined the temperature dependence of the characteristic Debye temperature Θ, and calculated the mean frequencies (moments) of the phonon spectrum. We compare the parameter values obtained in this way with data for the compound La1.85Sr0.15CuO4 having similar crystal structure, but hole conductivity. The magnitude of the specific-heat discontinuity and consequently the effective electron mass in the “electronic” superconductor Pr1.85Ce0.15CuO4 is several times smaller than in the “hole” superconductor La1.85Sr0.15CuO4. The phonon spectrum in Pr1.85Ce0.15CuO4 in the low-energy region is somewhat “more rigid,” and in the high-energy region somewhat “softer” than in La1.85Sr0.15CuO4.