Doping dependence of the order parameter symmetry in Y0.8Ca0.2Ba2Cu3O7-delta

We have studied planar tunneling and Point Contact (PC) measurements on ove rdoped, [110] oriented, Y0.8Ca0.2Ba2Cu3O7-delta (YCBCO) films. PC measureme nts show a clear Andreev characteristics with a dip at zero bias. Tunneling contacts on the same samples show a sub gap of about 3 mV and a Gap Like F eature (GLF) at 12 mV. No Zero Bias Conductance Peak (ZBCP) is seen in any of our measurements. This reflects the absence of bound states, indicating that the order parameter cannot have the pure d(x2-y2) symmetry. The overal l data is best described by a d(x2-y2)+id(xy) Order Parameter (OP).