Preparation and spectral analysis of Bi4-xLaxTi3O12 ferroelectric thin films by metal-organic deposition method

Bi-4 Ti-3 O-12 (BIT) and Bi-3.25 La-0.75 Ti-3 O-12(BLT) precursor solutions were prepared using metal-organic deposition method. BIT and BLT ferroelectric thin films were grown on the polished single crystal Si substrates. Dry gel powders of precursor solution and ferroelectric thin films were analyzed by FTIR spectrum, Raman spectrum and ESEM The results show that crystal structure was translated completely from pyrochlore to perovskite at about 600 degrees C. The dimension of crystal particles enlarges with the increase in annealing temperature. The peaks of Ti-O and Bi-O bond shift to lower wavenumbers because of introducing La into B-4 Ti-3 O-12, and this phenomenon becomes distinct with rising temperature. When the heat treatment temperature is 500 degrees C, CH3OCH2CH2OH and CH3COCH2COCH3 in dry gel completely decompose and volatilize. Water molecules volatilize and nitrate ions decompose completely over 600 degrees C.