Doping effect on the evolution of the pairing symmetry in n-type   superconductor near antiferromagnetic phase boundary
  We present the investigation results of the in-plane \{rho}(T) resistivity tensor at the temperature range 0.4-40 K in magnetic fields up to 90kOe (H||c, J||ab) for electron-doped Nd{2-x}Ce{x}CuO{4+{\delta}} with different degree of disorder near antiferromagnetic - superconducting phase boundary. We have experimentally found that for optimally doped compound both the upper critical field slope and the critical temperature decrease with increasing of the disorder parameter (d-wave pairing) while in the case of the underdoped system the critical temperature remains constant and (dHc2/dT)|Tc increases with increasing of the disorder (s-wave pairing). These features suggest a possible implementation of the complex mixture state as the (s+id)-pairing. 
T. B. Charikova, N. G. Shelushinina, G. I. Harus, V. N. Neverov, D. S.   Petukhov, O. E. Petukhova, A. A. Ivanov
cond-mat.supr-con