Dielectric and Piezoelectric Properties of Ca1-x(Li, Ce)x/2Bi4Ti4O15 Ceramics

The influence of (Li, Ce)(4+) on the properties (piezoelectric, dielectric ferroelectric properties) of bismuth layer (Ca(1-x)(Li, Ce)(x/2)Bi(4)Ti(4)O(15))(CLCBT) lead free piezoelectric ceramics used for high frequency and high temperature were investigated by means of conventional solid state method. The relationship between the additive amount of (Li, Ce)(4+) and the properties of CLCBT ceramics were obtained. The influences of additive amount of (Li, Ce)(4+) on the microstructure and material phase of CLCBT ceramics were studied by scanning electron microscope and X-ray diffraction. The mechanism for modifying the properties and microstructure of the CLCBT ceramics by (Li, Ce)(4+) doping was investigated. Results showed that the lead free bismuth layer CLCBT ceramics having good comprehensive properties was obtained when the (Li, Ce)(4+) additive amount was 0.075 mol, which the dielectric constant was 176.52, the dielectric loss was 0.00579, and the piezoelectric strain constant was 13 pC . N(-1). This materials was suitable to be used for high frequency and high temperature piezoelectric device, and so on. (Li, Ce)(4+) doping could affect the properties and microstructure of bismuth layer CLCBT ceramics by means of (Li, Ce)(4+) substituting for Ca(2+) in CLCBT, forming pyrochlore, densifying ceramics, stopping grain growing, forming Ca vacancy, and increasing specific resistance.