ABSTRACT
Photoacoustic spectroscopy has been used to study various sizes of nanoscaled CoTiO3 and NiTiO3 powders. Three absorption bands (or peaks) are observed in the photoacoustic spectra from ultraviolet to near-infrared (350nm ~1200nm) for each material, which are corresponding to transitions of excitons and electrons from three additional energy levels in energy gap. The behavior of the characterized absorption strongly depends on the grain sizes.
