The piezoelectric strain constant d33 of PZT-4 ceramics with electrode can drop from 380 pC/N to 0 by CO2 laser irradiation under suitable laser power density when the irradiation time is 2 s,5 s and 10 s at normal temperature and pressure.The relationships between d33 of PZT-4 ceramics and laser power density and laser irradiation time are investigated systematically.Based upon the characterization of XRD,Raman spectra and traditional annealing treatment,it is suggested the electric domains of irradiated P...