SrCaBi_4Ti_5O_(18)-BiMeO+3(Me=Ga,Mn)高温无铅压电陶瓷的制备及性能

采用固相合成法制备了(1-x)SrCaBi_4Ti_5O_(18-x)BiMeO_3(SCBT-xBMe,Me=Ga,Mn;0≤x≤0.02)铋层状压电陶瓷,研究了BiMeO_3掺杂对SrCaBi_4Ti_5O_(18)系陶瓷微观结构及电性能的影响。结果表明BiMeO_3掺杂并未改变SCBT陶瓷的晶体结构,所有样品均为单一的铋层状结构陶瓷;适量引入BiMeO_3能促使SCBT的晶粒长大且趋于均匀,并有助于SCBT电性能的优化。当BiMeO_3掺杂量为0.005(Me=Ga)和0.02(Me=Mn)时,材料的压电常数d33分别为18pC/N和20pC/N,同时材料具有高的居里温度(Tc=550℃)和低的介电损耗(tanδ0.15%)。此外,SCBTxBMe材料具有良好的压电稳定性,适合于制备高温高频压电器件。

Preparation and Properties of SrCaBi4Ti5O18-BiMeO3 (Me=Ga,Mn)High-temperature Lead-free Piezoelectric Ceramics

Bismuth layer-structured ferroelectric ceramics of (1-x) SrCaBi4Ti5O18-xBiMeO3 (SCBT-xBMe,Me=Ga,Mn;0 ≤x≤0.02) were prepared by traditional solid state reaction.The effects of BiMeO3 doping on the microstructure and electrical properties of ceramics were studied.Results indicated that all ceramics show bismuth oxide layered structure.After BiMeO3 doping,the grain size of the ceramics increased and became more uniform.Moreover,certain amount of BiMeO3 doping enhanced the electrical properties.When x=0.005 (BiGaO3) and x=0.02 (BiMnO3),the piezoelectric constant d33 reached 18pC/N and 20pC/N,respectively,together with high curie temperature (Tc =550℃) and low dielectric loss (tanδ＜ 0.15％).Moreover,the results of dielectric properties and thermal annealing behavior indicated that the SCBT-xBMe ceramics possessed high piezoelectric stability,which makes this material promising for high-temperature and high-frequency piezoelectric devices.