The Research On Electrical Properties Of Lead-Free BaTiO₃-Bi?Me?O₃ Dielectric Ceramics

With rapid development of science and technology demands the electronic devices should be miniaturization high capacity.Due to the excellent electronic properties,perovskite materials have been extensively researched and application,such as sensor,capacitor,transducers,filter BaTiO₃-based perovskite materials have high permittivity and harmless to environment,indicating that they are promising substitutes for PbTiO₃-Based materials.However,pure BaTiO₃ ceramic exhibited high sintering temperature,¹400^oC and three phase transitions at about 130°C,0°C,-90°C,leading to highly and strongly temperature-sensitive dielectric properties and a serious deterioration in permittivity,which restricts its further application in the electronic information manufacturing.Therefore,it is very important to develop high-performance BaTiO₃-based perovskite materials with high and stable permittivity to satisfy the requirement of electronic components.Recently,BiMeO₃perovskite materials have received much attention because BiMeO₃ compounds will effectively improve the dielectric properties of ceramics and reduced sintered temperature,where Me can be Al³⁺?Y³⁺?(Zn_1/2Ti_1/2)³⁺?(Mg_1/2Zr_1/2)³⁺etc.Inthiswork,?1-x?BaTiO3-x Bi?Li1/3Zr2/3?O3?BT-BLZ???1-x?BaTiO₃-xBi(Li_3/5W_2/5)O₃?BT-BLW???1-x?BaTiO₃-Bi(Ni_2/3Nb_1/3)O₃?BT-BNN??1-x?BaTiO₃-Bi(Mg_2/3V_1/3)O₃?BT-BMV???1-x?Ba_0.8Ca_0.2TiO₃-xBi(Mg_0.5Zr_0.5)O₃?BMZ?solid solution ceramics were prepared by a conventional solid state reaction technique using the idea of doping modification process.The effects of different additions on the phase structure,microstructure and electrical properties of BaTiO₃-base ceramics were systematically studied.XRD and dielectric measurement confirmed that the phase of BT-BLZ,BT-BLW,BT-BNN,BT-BMV,BCT-BMZ transformed form tetragonal to pseudocubic with increasing the addition contents.High thermal stability of permittivity,larger relative permittivity and low dielectric loss were obtained with small amount addition contents.When x=0.1,?1-x?BT-xBLZ samples possessed optimum dielectric performance with good thermal stability of permittivity(??/?_25°C?±15%)over a broad temperature range from-70°C to 144°C and low dielectric loss??2%?.Furthermore,BT with added small amount of BLW,the dielectric properties of BT-BLW ceramics was intensely increase.When x=0.1,?1-x?BT-xBNN samples with high dielectric constant?1000-1100?and low dielectric loss??2%?and samll variation of permittivity(??/?_25°C?±15%)were obtained.For x=0.2?1-x?BT-xBMV samples possessed samll variztion permittivity(??/?_25°C?±15%)range of 25-300^oC.When x=0.3,BCT-xBMZ samples with temperature stability of permittivity increased(??/?_27°C?±15%)and low dielectric loss??2%?over a wide temperature range from 27°C to 290°C at 1 kHz were got.The first characteristic dielectric peak could not be observed above 27°C and?_m could not be defined clearly.