Microstructural Studies of Milled and Annealed ZnFe 2 O 4 Nanostructures Using X-Ray Diffraction and Mössbauer Spectroscopy

Abstract

Nanostructured zinc ferrite ZnFe 2 O 4 was milled at high energy during 12 hours and then the portions of the obtained powders were calcined at 400℃ and 600℃ during 24 hours. X-ray diffractogramms recorded for various samples show that compared to the grain size value of as-prepared sample the average grain size obtaining from the milling process decreases after 12 hours of milling duration and increases with increasing annealing temperature. Then, the inversion and lattice parameters increase with milling process and decrease with increasing annealing temperature. Magnetic behaviours analyzed by means of 57Fe Mössbauer spectra recorded at 300K and 77K indicate that only milled sample without annealing is magnetically ordered at room temperature. At 77K, spectrum of milled zinc ferrite displays a magnetic state confirming the existence of cationic distribution after milling duration whereas the spectra of annealed samples exhibit the presence of superparamagnetic state.