用改进的sol-gel法制备锆钛酸铅薄膜及其物相转化的研究

CHARACTERIZATION OF PHASE TRANSFORMATIONS IN PZT THIN FILMS PREPARED BY A MODIFIED SOL-GEL TECHNIQUE

利用改进的sol gel法 ,在Pt/Ti/SiO2 /Si衬底上制备了PbZr0 .5Ti0 .5O3(PZT5 0 / 5 0 )薄膜 .采用了一种新的方式 ,从同一前驱体溶液得到了厚度各异的单一退火层 .研究了薄膜的结构和性质随单层退火厚度的改变而发生的变化 ,发现随着单一退火层厚度的降低 ,薄膜 ( 111)取向的程度增大 ,同时薄膜的剩余极化和介电常量也逐渐增高 .当单一退火层厚度降低到约为 4 0nm时 ,可得到高度 ( 111)择优取向的PZT薄膜 .从薄膜成核机理的基础上讨论了薄膜结构变化的内在因素 ,认为随单一退火层厚度的增加薄膜由单一的成核机理占主导作用 ,逐渐演变为两种成核机理同时起作用 .

A novel method for preparing PbZr\-\{0.5\}Ti\-\{0.5\}O\-3(PZT50/50) thin films with different thicknesses of single\|annealed layer has been applied in a modified sol\|gel process. The effect of the thickness of single\|annealed layer on the structure and electric properties was studied. It is observed that the degree of (111) orientation for the PZT films increases with the reduction of single\|annealed layer thickness. As the thickness of single\|annealed layer drops to 40?nm, the film shows a high degree of (111) orientation. The decrease of single\|annealed layer thickness also leads to the increase of the remanent polarization and dielectric constant. The formation of (111) preferred orientation in PZT50/50 films is considered to be the result of the heterogeneous nucleation mechanism.