Morphology and Magnetic Properties of Fe/fe-oxide Core/shell Nanoparticle Prepared by Highenergy Milling Process in Varied Medium

This article discussed about milling process result of Femicrometer powder using high energy milling facillity SPEX 8000M on aquabidest, isoprophyl alcohol and Cethyl Trimethyl Ammonium Bromide (CTAB) liquid medium. The mixture were placed on stainless steel vial and Stainless Steel balls were added with weight ratio between powder and balls of 1 : 5. Structure and phase of resulted nanoparticles were analized from image and Selective Area Electron Diffraction (SAED) pattern observed by Transmission Electron Microscope (TEM). Magnetic properties were determined from hysteresis curve measured by Vibrating Sample Magnetometer (VSM). TEM image and SAED pattern showed the formation of Fe/Fe-oxide core/shell structure especially for powder milled in isoprophyl alcohol medium. Spherical particles having around 40 nm size with Fe core diameter of 30 nm and Fe-oxide shell thickness of 5 nm were provided in this medium. For another medium, unspherical and unhomogenize nanoparticles tend to be formed eventhough the core/shell structure still could be observed. These structures gave the end result of high saturation magnetization value of Ms = 175 emu/grams for isoprophyl alcohol system and lower for another system. This magnetization value also stable with time for isoprophyl alcohol system showing the more non oxidative surface protection.