SINTESIS NANOPARTIKEL ZINC FERRITE (ZnFe2O4) DENGAN METODE KOPRESIPITASI DAN KARAKTERISASI SIFAT KEMAGNETANNYA

Zinc Ferrite Nanoparticles (ZnFe2O4) have been synthesized by co-precipitation method. The nanoparticles were synthesized with various concentration of NaOH 1,5 M; 3 M and 6 M and synthesis temperature at room temperature, 60 ⁰C. The characterization of the crystal structure and morphology of samples by using X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) showed that the samples were phase ZnFe2O4 with mixture of normal and inverse spinel structures. The particle size estimated using the Scherrer formula were found that the particle size decrease with increasing of NaOH concentrations and decreasing of synthesis temperature. The particle size samples with various concentration of NaOH of 1.5; 3 and 6 M are 8.4; 7.3 and 5.6 nmrespectively, whereas with various synthesis temperature of room temperature, 60 and 90⁰C and 90⁰C are 8.1; 8.4 and 9.2 nm, respectively. Characterization of magnetic properties by using Vibrating Sample Magnetometer (VSM) showed that the samples with various concentration of NaOH has a coercivity increases with decreasing particle size. Meanwhile for several of synthesis temperature, the increasing of particle size, than the coercivity tends to increase. At 15 kOe, the particle of size 5.6 nm with the
lowest phase ratio of α-Fe₂O₃ has the highest magnetization of 16.510 emu/g and the highest coercivity of 47.06 Oe. Based on the results it can be concluded that the particle size and the appearance of α-Fe₂O₃ influence the magnetic properties of ZnFe₂O4 nanoparticle.