Oxygen isotope effect in LaSrCuO system with T c modified by Ni and Zn doping

Abstract

The effect of the oxygen isotope substitution on the superconducting transition temperature T c has been studied in La 1.85Sr 0.15Cu 1−xNi xO 4 (x=0; 0.005; 0.01; 0.015; 0.02; 0.025; 0.03), La 1.85Sr 0.15Cu 1−xZn x O 4 (x = 0.0; 0.1) and La 2−xCa xCuO 4 (x = 0.1; 0.08) oxides. The isotope shift exponent α increases with the T c fall down. The results are in a good agreement with the BSC based theory of magnetic pair breaking.