Relaxor ferroelectrics with lanthanum perovskites

Lanthanum perovskite compounds La(B/sub 1/2//sup I/B/sub 1/2//sup II/)O/sub 3/ (B/sup I/=Ni,Co,Mg; B/sup II/=Ti) are studied as candidates for stabilizers to form perovskite-type Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/ (PZN)-based ceramics. A conventional sintering technique is used to prepare ceramic samples with PZN-based solid solution. The ratios of the perovskite phase to the pyrochlore phase were more than 90% at 10 mol.%-modification of La(Ni/sub 1/2/Ti/sub 1/2/)O/sub 3/ (LNT), La(Mg/sub 1/2/Ti/sub 1/2/)O/sub 3/ (LMT) or La(Co/sub 1/2/Ti/sub 1/2/)O/sub 3/ (LCT). The suppression of the pyrochlore phase in these ceramics is evaluated. The transverse electrostrictive strain, S/sub 1/ approximately -0.75*10/sup -4/, is induced by an electric field of 30 kV/cm in the thickness direction in the 5 mol.%-LNT modified PZN-based ceramics. The magnitude of strain is rather small, but the strain hysteresis is very small as compared with corresponding values for piezoelectric ceramics.<>