Preparation And Properties Of BNT Based Lead-free Piezoelectric Film

Piezoelectric materials is now widely used in the daily life,the application oftraditional piezoelectric material by using Pb(Ti,Zr)O3based materials,but the leadpiezoelectric materials will pollute the environment seriously.At present,people areattaching increasing importance to protect environmental,there is an urgent need for anew type of environmentally friendly materials to replace Pb(Ti,Zr)O3.In a lot oflead-free piezoelectric materials,sodium bismuth titanate(Bi0.5Na0.5TiO3) with itsexcellent performance,becoming the lead-free piezoelectric materials with greatpotential and are most likely to replace lead zirconate titanate.When sodiumbismuth(BNT) at room temperature trigonal system,its Curie temperature of320℃,with good piezoelectric properties,ferroelectric properties,acoustic propertiesand dielectric properties.But the drawback of BNT material is its high coercivefield,the leakage current is too large,these drawbacks limit its further development.Inrecent years,the study material preparation process conditions and was modified toimprove material properties of materials.This paper also along the way,the specificcontents are as follows:This paper mainly introduces the development situation of piezoelectric materialdevelopment history and lead-free piezoelectric material,explains the performanceparameters of each of the piezoelectric material,and the topic selected topicbasis.Next,the film also introduces the characterization of several common methodsand the preparation of this article need to use the film equipment.We focus on the preparation of BNT films discussed precursor solutionconcentration,film thickness and annealing temperature on the microstructure andproperties of thin films,the analsis of the external conditions on the hysteresis loop testresults impact.After the above test analysis concluded that:BNT thin films prepared by the opimum condions, the precursor solution concentration of0.3mol/L,the number offive-layer spin coating,annealing temperature of670℃.Finally,we study the modified sodium bismuth titanate,for BNT films of K+doping,analysis of different K+concentration on,ferroelectric,piezoelectric,dielectricthin films prepared BNKT the effect is also discussed the influence of different aspectsof performance of the above films BNKT Bi/Na ratio.The best performance0.15BNKTfilm,remanent polarization Pris19.6μC/cm2,Ecis73.5kV/cm,leakage current film is1.78*10-6A/cm2, piezoelectric coefficient d33is105pm.