Synthesis and characterization of nanocrystalline MgAl_xFe_(2-x)O_4 ferrites

摘要

The structural and magnetic properties of the Al cosubstituted cubic spinel ferrite series MgAl_xFe_(2-x)O_4 (x = 0.0, 0.4, 0.8, and 1.0) synthesized through a coprecipitation method were characterized by means of x-ray powder diffraction, infrared (IR) spectroscopy, transmission electron microscopy (TEM), differential thermal analyses, and vibrating sample magnetometer. Lattice constants determined from x-ray diffraction (XRD) measurements exhibit a decrease with increasing Al~(3+) ions in the ferrites system. The particle size using TEM was ～33 nm for magnesium ferrite, which is in good agreement with values obtained by XRD method. The crystallization spinel formation for the parent ferrite MgFe_2O_4 using differential thermal analysis (DTA) technique was 454 ℃. The two main bands observed in the IR spectra (tetrahedral and octahedral) were in the range (568-628 cm~(-1)) and (431-460 cm~(-1)), respectively. Magnetization curve shows the highest value for the sample with concentration x = 0.4.