SINTESIS NANOPARTIKEL NICKEL FERRITE (NiFe2O4) DENGAN METODE KOPRESIPITASI BESERTA KARAKTERISASI STRUKTUR KRISTAL DAN SIFAT KEMAGNETANNYA; CHARACTERIZATION OF CRYSTAL STRUCTURES AND MAGNETIC PROPERTIES OF NICKEL FERRITE (NiFe2O4) NANOPARTICLES PREPARED BY CO-PRECIPITATION METHOD

Muflihatun, Edi Suharyadi

2015 | Disertasi | FMIPA

Nickel ferrite (NiFe2O4) nanoparticles have been synthesized by co-precipitation method by varying concentration of NaOH, temperature of the synthesis, and stirring duration. Crystal structure, grain size, and morphology of NiFe2O4 nanoparticles were determined by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The result showed that the grain sizes of the samples were affected by the synthesis parameter. The grain sizes estimated using the Scherrer formula were found that the grain size decreased with decreasing temperature synthesis and increasing concentration of NaOH and stirring duration. The grain sizes with concentration of NaOH 3, 5, and 10 M are 5.7; 4.3; and 4.2 nm, respectively, for the temperature variations 60, 80, and 150 °C are 4.2; 4.9; and 5.5 nm, respectively and for stirring duration 60, 90, and 120 minutes are 4.2; 3.9; and 3.6 nm, respectively. Fourier transform infrared (FTIR) analysis showed two absorption bands in the nickel ferrite structure related to octahedral and tetrahedral sites in the range of ~400-600 cm-1. The magnetic measurement using Vibrating Sample Magnetometer (VSM) showed that the sample is typical soft magnetic with its coercivity in the range of 42-47 Oe. The coercivity of the sample depend on the particle size. Samples with various concentration of NaOH and synthesis temperatures behave as multi-domain particle, while sample with various stirring duration behave as single-domain particle. The variation of magnetization (at 15 kOe) were strongly affected by the presence of an impurity phase hematite (?-Fe2O3).

Kata Kunci : nanoparticle; Nickel ferrite (NiFe2O4); co-precipitation