63,65Cu nuclear quadrupole resonance study of YBa2(Cu1−xNix)3O7−δ

63,65Cu nuclear quadrupole resonance (NQR) spectra of YBa2(Cu1−xNix)3O7−δ have been measured at room temperature. When Ni is substituted for Cu, 63,65Cu NQR line widths increase significantly for both the Cu(2) plane site and the Cu(1) chain site. The asymmetric broadening of Cu(1) can be identified with the emergence of a new peak, whereas the Cu(2) signal shows nearly symmetrical broadening. Our results support that Ni substitute not only for Cu(2) on the conducting plane but also for Cu(1) on the chain in YBa2(Cu1−xNix)3O7−δ.