NANOCRYSTALLINE POWDER AND THIN-FILMS OF CALCIUM AND LANTHANUM-MODIFIED LEAD TITANATE BY THE SOL-GEL PROCESS

Nanocrystalline powder and thin films of calcium and lanthanum modifie d lead titanate (PCLT) were prepared by the sol-gel process. The struc tural variation of the powder with increasing annealing temperature wa s monitored by differential thermal analysis, thermogravimetric analys is, infrared spectroscopy and x-ray diffraction. The lowest temperatur e for the formation of nanocrystals was found to be about 400 degrees C. The size of the crystallites was calculated from x-ray diffraction data using Scherrer's equation. PCLT thin films were fabricated by spi n-coating a sol-gel solution onto Si(100) substrates. By controlling t he concentration of the precursor and the annealing temperature, homog eneous and crack-free thin films have been successfully prepared.