Stripe motion in CuO 2 planes of Y 1− x Pr x Ba 2 Cu 3 O 7 as observed from the Cu(2) quadrupole resonance

The NQR spectra of copper in the compounds YBa 2 Cu 3 O 7 , TmBa 2 Cu 3 O 7 , and Y 0.9 Pr 0.1 Ba 2 Cu 3 O 7 at temperatures of 4.2–200 K are investigated by a pulsed NQR technique at frequencies of 28–33 MHz. Quantitative analysis of the spectra shows that the shape of the “plane” Cu(2) spectra is well described by using a model of 1D correlations of the charge and spin distribution in the CuO 2 planes (stripe correlations). In the undoped superconductors the charge-spin stripe structure moves fast in the CuO 2 planes, but doping the YBa 2 Cu 3 O 7 lattice with praseodymium slows this motion down.