Microstructure Study on Gd-doped BaTiO_3 Sol-gel Multilayer Thin Films using AFM for Optoelectronic Applications

摘要

Gadolinium doped barium titanate (Gd-BaTiO_3) thin films with the molar ratio of 70:30 have been fabricated on SiO_2/Si substrates using sol-gel technique. The effect of number of deposited layers on the grain size and surface morphology has been investigated using an atomic force microscope in contact mode. AFM micro-images show that the films have well distributed grains, dense and crack free surface. In general, the results show that the grain size increases from ～170 nm to ～189 nm as the number of deposited layers increase from one to four layers which attributed to the grain growth mechanism during heating and annealing processes. However, the surface of the films is analysed through amplitude parameters to find out that the films surface is smooth with a predominant for peaks and relatively low number of high peaks and low valleys.