HIGH PIEZOELECTRIC PERFORMANCE AND RELEVANT PHYSICAL MECHANISM OF CuO-MODIFIED Ba(Ti_(0.96)Sn_(0.04))O_(3)CERAMICS

Ba(Ti_(0.96)Sn_(0.04))O_(3)and CuO-modified Ba(Ti_(0.96)Sn_(0.04))O_(3)ceramics were prepared by the solid state reaction technique.Their piezoelectric properties were investigated and compared with those of the recently obtained high-d_(33)BaTiO_(3)ceramic.It has been found that simply substituting Ti4t with Sn4t worsens severely the piezoelectric properties whereas a combined usage of CuO additive greatly improves the overall piezoelectric performance.CuO-modified BaeTi_(0.96)Sn_(0.04)TO_(3)ceramic shows excellent piezoelectric properties of d_(33)=390 pC=N;kp=0.49 and k33=0.67 at room temperature.Furthermore,it possesses weak temperature dependences of electromechanical coe±cients between
20 and 55 and a good thermal aging stability down to a low experimental temperature limit of
50℃and up to 90.Detailed analysis suggests that its high piezoelectric performance should be largely ascribed to the ideal microstructure of high relative density and small grains and the corresponding domain configurations.