Effect of Synthesis Parameters on Crystals Structures and Magnetic Properties of Cobalt Nickel Ferrite Nanoparticles

Abstract

Co0.5Ni0.5Fe2O4 magnetic nanoparticles have been successfully synthesized by coprecipitation method with varying synthesis temperature and NaOH concentration. X-ray diffraction (XRD) analysis confirmed that Co0.5Ni0.5Fe2O4 nanoparticles have spinel cubic crystal structure. The particle size of the sample synthesized at 3 M NaOH was 7.3 nm and then increased with the increase of NaOH concentration. It is caused by the increase of particle growth rate. The particle size of the sample synthesized at 30 °C was 10.2 nm and then increased with the increase of temperature. The lattice parameter of the sample was constant at 8.5 Å with varying synthesis temperature and NaOH concentration. The maximum magnetization and the coercivity of the sample synthesized at 3 M NaOH was 11.3 emu•g-1 and 0.1 kOe, respectively, and then increased with the increase of NaOH concentration. It is caused by the increase of crystallite size in a single domain. The maximum magnetization and the coercivity of the sample synthesized at 30 °C was 9.9 emu•g-1 and 0.1 kOe, respectively, and then increased with the increase of temperature. Transmission Electron Microscopy (TEM) image showed that the sample was agglomerated. Selective Area Electron Diffraction (SAED) image shows that sample is confirmed peak is appearing in XRD. The Fourier Transform Infra-Red (FTIR) spectra confirmed that vibration of octahedral and tetrahedral metal-oxide bond is 601.8 cm-1 and 370.3 cm-1. The purpose of this work is to investigate the effect of synthesis temperature and NaOH concentration on the relation between crystal structure and magnetic properties.