Electrostrictive behavior of lead magnesium niobate based ceramic dielectrics

Abstract

Abstract The electrostrictive strains induced by high electric fields have been measured for compositions in the solid solution system Pb(Mg1/3Nb2/3)O3: PbTiO3 (PMN:PT) containing up to 20 mole% PT. Large anhysteretic quadratic strains (up to 1,000 × 10−6) can be induced at room temperature with no evidence of remanence. In pure Pb (Mg1/3Nb2/3) O3 the electrostriction constants Q 11 and Q 12 are significantly smaller than in normal perovskites and the large induced strains may be traced to the high polarizability of the relaxor. With the addition of PT, the Q constants increase and the relaxation range shortens, with compositions close to 10 mole% PT providing maximum quadratic sensitivity. Over the relaxation range of temperatures, the thermal expansion is extremely small and comparable to the best thermally stable glasses and ceramics.