Effect of Ti substitution on the residual resistivity in the spin-triplet superconductor Sr2RuO4

We report the substitution effect of nonmagnetic Ti4+ for Ru4+ on the in-plane resistivity of Sr2Ru1-xTiO4 with x from 0 (spin-triplet superconductor) to 0.03 (the border of the magnetically ordered phase). The superconductivity is suppressed by a small amount of Ti with x similar to 10(-3) reflecting the extreme sensitivity to translational symmetry breaking. In addition, the in-plane residual resistivity is proportional to x in quantitative agreement with the isotropic scattering in the unitarity limit in a two-dimensional system. This indicates that the nonmagnetic impurity in Sr2RuO4 acts as a strong potential scatterer, similar to the Zn impurity in the cuprates. (C) 2002 Elsevier Science B.V. All rights reserved.