Electrical Properties Research And Preparation Of Barium Titanate Ceramic Based On Nano-scale Precursors

Piezoelectric material is a kind of functional material which can realize the conversion of electric energy and mechanical energy.It has a wide range of applications in industrial production and daily life,such as power supply systems,sensors and transducers,and it has important practical value in the energy and electronics industries.Since PZT-based piezoelectric ceramics have been discovered,it has been widely concerned and occupied most of the piezoelectric materials market.However,lead-based piezoelectric ceramics can cause irrevers ible damage to the environment during the production,use and disposal processes.Therefore,the lead-free piezoelectric ceramics has become the inevitable trend of the development of piezoelectric materials,and it is also the inevitable choice to build an environment-friendly society.In this paper,based on the study of the piezoelectric properties of barium titanate piezoelectric ceramics,the prospect and development trend of barium titanate piezoelectric ceramics in practical application were further explored.The ultrafine titanium dioxide particles synthesized by liquid phase method and commercial nano-barium carbonate were used as nano-precursors to prepare barium titanate piezoelectric ceramics by solid phase method.And the effect of sintering temperature on its performance was further studied.taThe flexible composite piezoelectric film was formed by combining the flexible material?PDMS?with the piezoelectric material powder,which retained most of the piezoelectric properties and overcame its fragility and improves its practicability.The specific contents of this paper are as follows.?1?Barium titanate piezoelectric ceramics were prepared using solid phase reaction.The effects of nano-precursor and sintering temperature on the particle size and properties of ceramics were studied.The results showed that nano-precursors play an important role in improving the size uniformity and compactness of ceramics.The grain growth of barium titanate ceramics based on nano-precursor was better and the particles are relatively abundant.Different sintering temperatures had a significant effect on the microstructure,purity,particle size and compactness of barium titanate ceramics.As the sintering temperature increased moderately,the purity,morphology?particle size and compactness?and performance?dielectric constant,residual polarization intensity and piezoelectric coefficient?were improved.?2?BaTiO₃ / PDMS flexible composite piezoelectric thin films were prepared by the method of spin coating with barium titanate powder and PDMS.And its piezoelectric properties were studied in four aspects: barium titanate powder,different barium titanate content,different film thickness and carbon modification.The results showed that the piezoelectric film produced by solid-phase synthesis of barium titanate had better performance,and its piezoelectric output characteristic increased with the increase of BaTiO₃ content,and the maximum output was 9.0 V and 5.2 ?A,respectively.As the film thickness increased,the large voltage output increased from 2 V to 6.5 V.In addition,the incorporation of an appropriate amount of carbon black?BaTiO₃: carbon black 10: 1?could optimize the performance of the piezoelectric film and the voltage output was about 13.5V.Finally,the piezoelectric film was used to charge the capacitor to drive the LED lamp to study its practical application of the feasibility and its stability and persistence were studied by repeated cycling tests.