نوع مقاله : مقاله پژوهشی کامل
نویسندگان
1 آزمایشگاه تحقیقاتی مغناطیس و ابررسانایی، گروه فیزیک، دانشگاه بیرجند
2 2دانشکده علوم، گروه فیزیک، دانشگاه فردوسی مشهد
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this research, magnesium ferrite nanoparticles (MgFe2O4) were synthesized by sol-gel auto combustion method using precursors with different pH values. The structural properties of the calcinated samples were studied by X-ray diffraction (XRD). In all of the samples, the desired phase of ferrite was completely formed. The mean crystallite size, which was estimated by using the Scherer equation, had no significant change with increase of pH and was about 20nm. These variations are due to ion distribution change on the lattice sites. The accurate value and distribution of the size of nanoparticles were investigated by probing transmission electron microscopy (TEM). The results showed that the growth of nanoparticles and their distribution changed with increasing the pH value. Nanopowders at pH=7 were homogeneous and no agglomeration was observed and their size was about 30nm. The magnetic properties of nanoparticles were measured by a vibrating sample magnetometer (VSM). Increasing the pH value gave rise to reducing the MS from 26.32 to 19.61 emu/gr, and the variation of HC between 74.06 and 89.74 Oe. These changes might be due to the variation in size, distribution of ions, canting effects and shape and magneto crystalline anisotropies of nanoparticles.
کلیدواژهها [English]
)