  We studied Zn-substitution effect on the high-T_c superconductors, underdoped
La_{2-x}Sr_xCu_{1-y}Zn_yO_4 (x=0.10; y=0, 0.01, 0.02), optimally doped (x=0.15;
y=0, 0.02), and overdoped (x=0.20; y=0, 0.03, 0.06) in a temperature range of
T=4.2-300 K, using Cu nuclear quadrupole resonance (NQR) spin-echo technique.
We found full disappearance of the Cu NQR signals for the Zn-substituted,
Sr-underdoped x=0.10 samples below about 40 K, partial disappearance for the
Sr-optimally doped ones below about 50 K, but not for the overdoped x=0.20
ones. From the Zn-doping, the Sr-doping and the temperature dependence of the
wipeout effect, we associate the wipeout effect with Zn-induced Curie magnetism
or its extended glassy charge-spin stripe formation.
