Abstract
Four superconducting single crystals near the optimum-doped region (x=0, 0.11, 0.17, and 0.28) for the Bi 2 Sr 2 Ca 1-x Pr x Cu 2 O 8+δ system were chosen for detailed structural and magnetic measurements, in order to study the effect of Pr scattering on the temperature dependence of the ab-plane penetration depth λ ab . The penetration depth for these incommensurate modulated single crystals follows a T 2 behavior at low temperature, and then crossover to a linear T dependence at the characteristic temperature T*. Variation of linear T region and T* with increasing Pr content indicates that Pr acts as a strong scattering center that modifies the local density of states of the system. The present result is consistent with the prediction for disorder-affected d-wave superconductors.