Mossbauer and Magnetic Studies ofManganese Ferrite; Fine Particles and Thin Films

Abstract

Recently ferrite systems have received a great deal of interest as fine magnetic particle and thin films for a wide range of applications in ceramics and magnetic media technology. Magnetic properties of fine particles differ drastically from those of the corresponding bulk materials. This difference in properties is the results of various effects due to magnetic interactions between small particles. X-ray diffraction, magnetization measurements and Mossbauer spectroscopy are used to investigate structural and magnetic evolutions of manganese ferrite processed by high energy ball milling. Milling processes reduce the average particle size of the samples after relatively short periods of time. An increase in the inversion parameter is observed with increasing the milling time. Magnetization measurements show that the ball-milled samples have different properties than that of the bulk. As a result of spin canting rearrangement, the saturation magnetization decreases with decreasing the average particle size. It is found that this canting related to a surface layer in which the spins are inclined to the direction of the net • magnetic moment.

Another important aspect of the present study is to investigate the magnetic properties of polycrystalline manganese ferrite films processed by pulsed laser deposition method. MnFe204 target is