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采用Sol-Gel工艺低温制备了Si基Bi3·25La0·75Ti3O12铁电薄膜.研究了退火温度对薄膜微观结构、介电特性与铁电性能的影响.500℃退火处理的Bi3·25La0·75Ti3O12薄膜未能充分晶化,晶粒细小且有非晶团聚,介电与铁电性能均较差.高于550℃退火处理的Bi3·25La0·75Ti3O12薄膜表面平整无裂纹,晶粒均匀,无焦碌石相或其他杂相,薄膜为多晶生长,具有较好的介电与铁电性能,4V电压下的漏电流密度低于2×10-8A/cm2.随退火温度升高,晶化程度的提升和晶粒尺寸的增大使薄膜的剩余极化增大而矫顽电场降低.600℃退火处理的Bi3·25La0·75Ti3O12薄膜显示了优于Bi4Ti3O12薄膜的铁电性能,其剩余极化Pr和矫顽电场Ec分别达到17·5μC/cm2和102kV/cm.
The Si-based Bi3.25La0.73Ti3O12 ferroelectric thin films were prepared by Sol-Gel process at low temperature.The effects of annealing temperature on the microstructure, dielectric properties and ferroelectric properties of the films were studied.The thin films of Bi3.25La0.75Ti3O12 annealed at 500 ℃ Can be fully crystallized, small grains and amorphous agglomeration, the dielectric and ferroelectric properties are poor.After annealed at 550 ℃, the surface of Bi3.25La0.775Ti3O12 film is flat and crack-free, with uniform grains and no coke Phase or other miscellaneous phase, the film is polycrystalline growth, has good dielectric and ferroelectric properties, 4V voltage leakage current density of less than 2 × 10-8A / cm2. With the annealing temperature increases, the degree of crystallization The remanent polarization and the coercive electric field of the film increase with the increase of the grain size and the increase of the grain size.The Bi3.25La0.75Ti3O12 film annealed at 600 ℃ shows better ferroelectric properties than the Bi4Ti3O12 film with remanent polarization Pr The stubborn field Ec reached 17.5μC / cm2 and 102kV / cm, respectively.