Induction of combinatory characteristics by relaxor modification of Pb(Zr[sub 0.5]Ti[sub 0.5])O[sub 3].

This letter reports a Pb(Zr[sub 0.5]Ti[sub 0.5])O[sub 3] (PZT) based composition, which provides high piezoelectric and electromechanical properties. The general form of the composition is Pb(Zn[sub 1/3]Nb[sub 2/3])[sub x](B[sub 1/3][sup I[sup ′]]B[sub 2/3][sup II[sup ′]])[sub y](Zr[sub 0.5]Ti[sub 0.5])[sub 1-x-y]O[sub 3]+0.5 wt % MnO[sub 2] (x+y=0.2). Four compositions corresponding to the earlier formulation were studied. For the composition corresponding to y=0, the radial mode coupling factor (k[sub p]) of 0.58, longitudinal mode piezoelectric constant (d[sub 33]) of 277 pC/N, dielectric constant ([variant_greek_epsilon][sub 33]/[variant_greek_epsilon][sub 0]) of 946, and mechanical quality factor (Q[sub m]) of 1402 are obtained. X-ray diffraction, dielectric, and polarization-electric field measurements were done to investigate the origin for this high performance. It was found that high soft properties are obtained due to the shifting of PZT composition towards morphotropic phase boundary and high hard properties are obtained due to the generation of dipolar defects which pin the polarization. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]