Zn-doping dependence of the wipeout region around Zn in YBa2(Cu1−xZnx)4O8

Abstract We estimated the spread of the magnetically enhanced regions (wipeout regions) around Zn ions in high- T c superconductors YBa 2 (Cu 1− x Zn x ) 4 O 8 ( x =0, 0.005, 0.01, and 0.022) at T =4.2 K, via the planar 63 Cu nuclear spin–lattice relaxation study with Cu nuclear quadrupole resonance spin-echo technique. From the analysis of nonexponential planar Cu nuclear spin–lattice relaxation curves, we found that the wipeout region per a Zn ion shrinks with Zn doping in the superconducting state. The shrinkage is associated with suppression of the host antiferromagnetic spin correlation, as a result from a dilution effect on the magnetic CuO 2 network.