Part II

Ahmed, M. A., S. T. Bishay, and E. -dekS. I. G. nd Omar, "Part II", Journal of Alloys and Compounds, 2011.


NixMn0.8?xMg0.2Fe2O4; 0.1 ? x ? 0.35 was prepared by standard ceramic technique at sintering temperature 1200 oC using heating / cooling rate 4 ?C/min. The samples were irradiated by Nd YAG pulsed laser with energy of the pulse 250 mJ. X-ray diffractograms reveal cubic spinel structure for all the samples before and after laser irradiation. After laser irradiation, better crystallinity was obtained in a form of an increase in the calculated crystal size. This increase was discussed as due to the change in the valence of some ions like Fe3+, Ni2+ and Mn2+. The conductivity of all the investigated samples decreases after laser irradiation and becomes temperature independent for a wider range than that before irradiation. Accordingly, these ferrites are recommended to be useful in electronic devices.