Different piezoelectric grain size effects in BaTiO3 ceramics

Four groups of barium titanate (BaTiO 3 ) ceramics with high piezoelectric coefficient have been successfully fabricated from different raw materials. Their average grain size ( g ) dependences of the piezoelectric coefficient d 33 were systematically studied. It was found that for two groups of BaTiO 3 ceramics, d 33 firstly increases and then decreases with the increase of g , with a maximum d 33 of 449   pC/N and 501   pC/N respectively at approximately 1   µm grain size, while for the other two groups of BaTiO 3 ceramics, d 33 keeps increasing with the increase of g . The highest d 33 of 401   pC/N and 424   pC/N were obtained when g is larger than 50   µm. The experimental results indicated that piezoelectric grain size effect in BaTiO 3 ceramics may be not absolute. Possible mechanisms arising from differences in domain configuration were discussed.