Magnetic-field dependence of the low-temperature specific heat of the electron-doped superconductor Pr 1.85 Ce 0.15 Cu O 4

We remeasured the magnetic field dependence of the low-temperature specific heat of the electron-doped superconductor Pr1.85Ce0.15CuO4 (T_C=22\pm 2K) under a different measurement procedure. Under field-cooling, the electronic specific heat follows C_{el}(H, T)=\gamma (H)T from 4.5K down to 1.8K. In the field range H_{C1}<H<0.5 H_{C2}, the Sommerfeld coefficient \gamma (H) is well fit by a power-law \gamma (H)\sim H^{1/2}. This result suggests that the pairing symmetry is d-wave-like at all temperatures below 4.5K. Our new measurement shows no evidence for the linear field dependence of \gamma (H) found previously at T=2K.