KAJIAN KEMAGNETAN PADA NANOPARTIKEL NICKEL FERRITE (NiFe2O4) YANG DIENKAPSULASI DENGAN POLYETHYLENE GLYCOL (PEG-4000) DAN SILIKA; STUDY OF MAGNETIC PROPERTIES OF POLYETHYLENE GLYCOL (PEG-4000) AND SILICA ENCAPSULATED NICKEL FERRITE (NiFe2O4) NANOPARTICLES

Shofiah, Siti, Edi Suharyadi

2015 | Disertasi | FMIPA

Magnetic nanoparticles of nickel ferrite (NiFe2O4) have been successfully encapsulated with various concentrations of PEG-4000 and silica, which used as materials for encapsulation. Aqueos solution of sodium silicate (Na2SiO3) used as precursor of silica. NiFe2O4 powder synthesized by copresipitation method. X-Ray Diffraction (XRD) showed that before and after encapsulated appears new phase on NiFe2O4. It was ?-Fe2O3 (hematite) which is antiferromagnetic. That phase was decrease sample response by external field. Encapsulated of silica, degree 2? = 21.96? and 25.83? showed shape of SiO2 phase. Lattice parameter before and after encapsulated are 8.39 ± 0.24 Å (NiFe2O4); 8.43 ± 0.13 Å (NiFe2O4+PEG-4000); and 8.27 ± 0.55 Å (NiFe2O4+silica). Particle size before and after encapsulated are 4.8 ± 0.2 nm (NiFe2O4); 1.6 ± 0.1 nm (NiFe2O4+PEG-4000); and 10.6 ± 0.3 nm (NiFe2O4+silica). Transmission Electron Microscopy (TEM) showed that encapsulated PEG-4000 and silica decreased agglomeration, controlled shape of nanoparticles more spherical and dispersed. Saturation magnetisation (

Kata Kunci : nickel ferrite (NiFe2O4); coprecipitation; encapsulation, PEG-4000; silica