X-RAYS DIFFRACTION STUDY ON THE IRON NANO PARTICLES PREPARED BY TWO STEPS MILLING METHOD

Abstract

X-RAYS DIFFRACTION STUDY ON THE IRON NANO PARTICLES PREPARED BY TWO STEPS MILLING METHOD. X-rays diffraction study on the iron nanoparticles prepared by two-step milling method has been carried out. First, the raw material of micro-sized Fe was crushed by High Energy Milling (HEM) in the presence of isopropyl alcohol, here in after referred to as FI precursor. FI precursor then was crushed again with planetary balls mill in Cetyl-Trimethyl- Ammonium Bromide (CTAB)media, here in after referred to as FC sample. The phases analysis in the two samples were carried out by X-rays diffraction technique using the Rietveld method. Crystallites size were calculated with the Debye-Scherrer formula and the size of particles were measured by means of Particles Size Analyzer (PSA). The magnetic properties of the two samples were characterized with Vibration Sample Magnetometer (VSM). The analysis result showed that each of FI and FC samples consist of Fe, γ-Fe₂O₃ and Fe₃O₄ phases in the formof the nano-sized powder ranging fromaround 7 to 10 nm. PSA data indicate that the particle size of FI and FC are the same, i.e., 7.5 nm with narrow size distribution. The VSM data revealed that both FI and FC samples display super paramagnetic behavior at room temperature. The magnetization value in FC sample has been reduced due to more of the mass fraction of Fe transforms into iron oxide phases. The particle size is generally not the same as the size of the crystallites and in particular for the nano-sized particles, the size of crystallites could be equal to or greater than the particle size due to the presence of polycrystalline aggregates.