Electrostriction in Lead Lanthanum Zirconate‐Titanate Ceramics

Electric polarizations and elastic strain were measured simultaneously for several lead lanthanum zirconate‐titanate (PLZT) compositions cycled around their high‐field electric hysteresis loops. Using the accepted symbolism for compositions, where the first number gives the mole percent of La 2 O 3 and the second two numbers give the ratio of PbZrO 3 to PbTiO 3 in the composition, data were taken for (7,7.5,8,8.8,9.5)/65/35 and 8/70/30 compositions. The results show that for all compositions in which the base state is macroscopically nonpolar, the strains are dominantly electro‐strictive in nature. Both of the polarization‐related constants, Q 11 and Q 12 , are almost independent of temperature and of the same order as in other perovskites but decrease slightly in magnitude with increasing La 2 O 3 content.