MODIFICATION OF PIEZOELECTRIC CHARACTERISTICS OF THE PB(MG,NB)O-3-PBZRO3-PBTIO3 TERNARY-SYSTEM BY ALIOVALENT ADDITIVES

The effects of donor and acceptor doping on the piezoelectric properti es of 18Pb(Mg1/3Nb2/3)O-3.39PbZrO(3).43PbTiO(3) ternary solid solution have been investigated. The dopants influence in a pronounced way bot h the crystal structure and microstructure of the materials. The mater ials are transformed from the rhombohedral to the tetragonal structure , and the grain size is reduced when Nb5+ cations are added. The cryst al structures are transformed from the rhombohedral to the cubic struc ture, and grain growth is enhanced, when Mg2+ cations are included. Th e values of K-p and K are maximized for 1-mol%-Nb5+-doped samples (K-p = 0.69, K = 1152); the Q(m) factor and E(c) are optimized for 4-mol%- Mg2+-doped samples (Q(m) = 1531, E(c) = 0.56).