Lattice Strain Analysis on Nanocrystalline Iron Oxide Composites as Environmental Catalysts

This work had the objective of studying the nanocrytalline iron oxide composites as environmental catalysts obtained by the modified sol -gel method, which is based on the formation of gel followed by a heat treatment in order to obtain the final oxide. the powders were calcined betwin500 and 900 c and characterized by X-ray diffraction XRD, FT-IR spectroscopy and scanning electronic microscopy SEM. the samples calcined at different temperatures were single phase with a cubic system and space group Fd3m( 2 2 7) . structural changes of the calcined samples at different temperatures were analyzed by powder X-ray diffraction XRD. the studies on the crystalline size and lattice strain with varying temperature were evaluated using williamson -Hall and scherrer methods. the crystalline sizes calculated by two different methods , reach nanometric scales. our results show that depending on the calcination temperature, the crystallite size appears to incrase with the heat treatment temperature , most likely due to the coalescence of crystallited that result in increasing the average size of the nanoparticles.

کلیدواژه ها:

Nanocrytalline ، iron oxide composites ، lattice strain analysis ، environmental catalysts.