Grain size effect on piezoelectric and ferroelectric properties of BaTiO3 ceramics

Abstract A series of dense barium titanate (BaTiO 3 , BTO) ceramics with different grain sizes (GS) were prepared by two-step sintering method. The effect of GS on piezoelectric coefficient ( d 33 ) and planar electromechanical coupling factor ( k p ) displayed a trend similar to that on relative permittivity ( ɛ ′). The values of d 33 , k p , and ɛ ′ increased significantly with decreasing GS, reaching maximum values ( ɛ ′ = 6079, d 33  = 519 pC/N and k p  = 39.5%) at approximately 1 μm, and then decreased rapidly with further decreasing GS. The results revealed that high-performance BTO ceramics could be effectively prepared by controlling GS. Polarization–electric field hysteresis loops and temperature dependence of ɛ′ were also investigated.