Si基Bi3.25La0.75Ti3O12铁电薄膜的制备与特性研究

采用Sol-Gel工艺低温制备了Si基Bi_3.25La_0.75Ti₃O₁₂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Bi_3.25La_0.75Ti₃O₁₂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Bi_3.25La_{0.75 关键词： 铁电薄膜 3.25}La_0.75Ti₃O₁₂')" href="#">Bi_3.25La_0.75Ti₃O₁₂ Sol-Gel工艺

Synthesis and characteristics of Bi3.25La0.75Ti3O12 ferroelectric thin films by sol-gel technology

Bi_3.25La_0.75Ti₃O₁₂ thin films were prepared on p-Si substrates by Sol-Gel technology. The effect of annealing temperature on microstructure, morphology, dielectric and ferroelectric properties of Bi_3.25La_0.75Ti₃O₁₂ films was investigated. Bi_3.25La_0.75Ti₃O₁₂ films annealed at 500℃ were not very uniform, they consisted of small grains and coarse grains with poor dielectric and ferroelectric properties. When the annealing temperature was over 550℃, Bi_3.25La_0.75Ti₃O₁₂ films were uniform and crack free as well as exhibiting no preferred orientation with good dielectric and ferroelectric properties. The leakage current density of Bi_3.25La_0.75Ti₃O₁₂ thin films is 2×10^-8A/cm² at 4V. A noticeable improvement of ferroelectric properties have been obtained when the annealing temperature was increased. Bi_3.25La_0.75Ti₃O₁₂ films annealed at 600℃ showed excellent dielectric and ferroelectric properties with a dielectric constant of 288, a dielectric loss of 1.57%, a remanent polarization of 17.5μC/cm² and a coercive field of 102kV/cm.