中文摘要：

研究了TiO2过渡层对BiFeO3薄膜微结构和铁电磁性质的影响.采用溶胶-凝胶法分别在Si（100）和Pt（111）/Ti/SiO2/Si（100）衬底上制备了BiFeO3薄膜.通过加入约10 nm厚度的TiO2过渡层,在两种衬底上均制备出了纯相BiFeO3薄膜,而未加过渡层的薄膜均有杂相存在.与未加TiO2过渡层相比较,BiFeO3/TiO2薄膜表面颗粒大小更加均匀、致密、平整.在室温10kHz下沉积在Pt/Ti/SiO2/Si衬底上的薄膜的损耗从0.094下降到0.028;而薄膜的介电常数变化不大,分别为177和161.在室温下同时测得了薄膜的电滞回线和磁滞回线.BiFeO3/TiO2薄膜的饱和磁化强度为16.8 emu/cm3,在600kV/cm电场下,剩余极化强度为9.8μC/cm2.研究表明,TiO2过渡层能够有效地抑制Bi FeO3薄膜杂相的生成,提高薄膜的表面平整度以及耐压性.

英文摘要：

The effect of TiO2 buffer layer on the microstructure and ferroelectric and magnetic properties of BiFeO3（BFO） films produced by a sol-gel method on both Si（100） and Pt（111）/Ti/SiO2/Si（100） substrates was studied.X-ray diffraction and atomic force microscope showed that the TiO2 buffer layer is critical for improving the crystallinity and surface roughness. Comparing with the films crystallized directly onto the Si and Pt/Ti/SiO2/Si substrates,the BFO films on an amorphous TiO2 buffer layer have pure perovskite phase without Bi2O3,Fe2O3 or Bi2Fe4O9 phases.At room temperature,obvious multiferroic behavior with the remanent polarization of 9.8 μC/cm2 and saturation magnetization of 16.8 emu/cm3 was observed in the films having TiO2 buffer layer.