The Preparation And Modified Of Barium Titanate Ceramic Capacitor And The Research Of Electrical Performance

This paper has carried on the comprehensive introduction of barium titanatepreparation technology in recent years. Developed by the inorganic material Ba(CH3COO)2as the source of barium, with cheap easy Ti {OCH (CH3)2}4as thetitanium source to prepare BaTiO3thin films by sol-gel method after comparing theadvantages and disadvantages of various methods. Then research BaTiO3thin filmswith infrared spectrum analysis; XRD analysis; SEM and TEM analysis; DSC thermalanalysis and TGA analysis and a series of characterization. And analyze the preparationconditions and sintering temperature on the influence of barium titanate thin film grainsize and phase. It is concluded that the best process conditions of preparation of bariumtitanate. Using the most economic materials, control solution PH material3.5; reactiontemperature85℃; sintering temperature1050℃, the barium titanate mainly exist infour phase, uniform particle size, size around200nm, no serious phenomenon ofreunion, to meet the requirements of the nano powder. In this way can calcine ceramicswith high dielectric constant, which laid a foundation for later manufacturing ceramiccapacitor.Modified BaTiO3powders with doping, replacement and surface coatingmodification to solve that BaTiO3ceramic dielectric constant in the working area ofunstable change and improve the dielectric constant and broaden the Curie peak. Aftersintering BaTiO3powder at1050℃by sol-gel method doped and replacement thedielectric constant, tt can reach9330to the biggest. No matter how low the sinteringtemperature of the dielectric constant is, the change of frequency is very stable. At thesame time, the dielectric loss is very small, about0.002, can meet the applicationrequirements of multilayer ceramic capacitors.Finally, coated the surface of BaTiO3with a layer of thickness Al2O3about10nmsuccessfully using Al (OC3H7)3as aluminum source, HNO3as peptizing agent, in the85℃.Combined with XRD figure mechanism of coating was studied. At the same timecombined with TEM test shows on the surface of BaTiO3powder coated Al2O3filmthickness uniformity, covering complete. The results of dielectric constant test provedthat the dielectric constant of BaTiO3powders coated with Al2O3film must beimproved. On the surface of A12O3@BaTiO3coated calcium magnesium aluminiumsilicate glass. Combined with TEM and SEM tests showed calcium magnesium silicon aluminate glass on Al2O3@BaTiO3powders is thickness and coating integrity. SEM andEDS proved the Ca, Mg, Al, Si and O elements. Due to the addition of calciummagnesium silicon aluminate glass, ceramic plate porosity is reduced, the densityincreased significantly, reducing the loss factor of material, makes the dielectricconstant increased to11000, the dielectric loss of0.0003or so.