PIEZOELECTRIC PROPERTIES OF NIOBIUM-DOPED [PB(SC1/2NB1/2)(1-X)TI-X]O-3 CERAMICS MATERIAL NEAR THE MORPHOTROPIC PHASE-BOUNDARY

The physical and electrical properties of Pb[(Sc1/2Nb1/2)(1-x)Ti-x]O-3(x=0.40-0.45)+0.01PbNb(2)O(6) piezoelectric polycrystalline ceramic materials near the morphotropic phase boundary (MPB) were investigated. The maximum dielectric constant (epsilon(33)(T)/epsilon(0)=3200) and maximum piezoelectric constant (d(33)=590x10(-12) m/V) were found at x=0.435, where the coupling factors mere k(p)=67%, k(31)=41%, and k(33)=74%. The maximum electromechanical coupling factors, (k(p)=71%, k(31)=44%, and k(33)=77%) were found at x:=0.420, where epsilon(33)(T)/epsilon(0)=2080 and d(33)=480x10(-12) m/V were obtained. The x=0.420 composition exhibited the largest electromechanical coupling factor of all binary piezoelectric ceramics systems so far reported, including the most widely used conventional ceramic, Pb((Zr-1-x, Ti-x)O-3.