Institute for Molecular Science, Okazaki National Research Institutes, Myodaiji, Okazaki 444, Japan
Abstract:
The effect of oxygen isotope substitution on the transition temperature Tc of a superconducting (Nd1?xCex)2CuO4?δ system was studied, where the special synthetic method was taken to minimize ambiguous factors on the oxygen concentration and to guarantee the complete substitution of 16O by 18O. The isotope exponent in the relationship of Tc∝1/M was estimated to be less than 0.15 by magnetic susceptibility measurements.