Preparation And Properties Of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ Piezoelectric Ceramic

Functional materials is an indispensable part of modern society,which play an important role in many fields.As an important branch of functional materials,Piezoelectric ceramic materials is widely used in sound,light inductor,energy conversion and electronics,but Piezoelectric ceramic materials are mainly based on lead,which is in conflict with sustainable development of environmental protection consciousness.Lead-free Piezoelectric ceramic materials dominate the mainstream study of Piezoelectric ceramic materials.Barium Titanate is the pillar of electronics,once found its good dielectric and piezoelectric properties from 1942,Barium Titanate has been developed rapidly.The(Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃?BCZT?ceramic,as a newly developed binary system piezoelectric ceramic,displays very high piezoelectric properties around morphotropic phase boundary?MPB?,which is similar with lead-based Piezoelectric ceramic.It is possible to substitute the lead-based Piezoelectric ceramic.But some shortages of BCZT constrain its practical application.BCZT is the object of our study,which is prepared by sol-gel method.Factors that have effect on the properties of the powder were discussed.In this work,the raw materials are ZrOCl₂·8H₂O,Ca?NO₃?₂.4H₂O,Ba?CH₃OO?₂,Cl₂H₂₈O₄Ti,BCZT powder was prepared by sol-gel method.Systematic method was used to study the controlling conditions.The aging time and calcination temperature have great influence on particle size and morphology.Particle size increased with the increase of aging time and calcinations temperature.When aging time is 12h,the smallest particle size can be obtained.The agglomeration augmented as the calcinations temperature increased.The sol-gel powder crystallized completely between 650? and 750?.all crystal size estimated by the line broadening of X-ray diffraction was below 50nm.The sintering temperature,micro structure and density was studied.Density increased with the increase of sintering temperature.The max density is obtained when the sintering temperature is 1400?.The ceramic surface is smooth and glossy between 1380? and 1420?.The piezoelectric and dielectric properties of BCZT ceramic were studied.As the sintering temperature increases,the relative dielectric constant increases initially,then decreases.The dielectric loss has a opposite trend with the increase of sintering temperature.The s-t curve of BCZT ceramic shows the phase transformation temperature.The electromechanical coupling coefficient of BCZT ceramic prepared by sol-gel is 0.51,which is bigger than those prepared by solid phase synthesis technique.