STUDI PENGARUH UKURAN BUTIR PARTIKEL DAN STRUKTUR KRISTAL TERHADAP SIFAT DIELEKTRIK NANOPARTIKEL COBALT FERRITE (CoFe2O4); STUDY ON THE INFLUENCE OF GRAIN SIZE AND CRYSTAL STRUCTURE ON DIELECTRIC PROPERTIES OF COBALT FERRITE (CoFe2O4) NANOPARTICLE

RAHMAT WIDODO, Edi Suharyadi

2014 | Disertasi | PROGRAM STUDI S-2 FISIKA

Cobalt Ferrite (CoFe2O4) has been synthesized with various grain size of particle of 4.3 nm, 7.7 nm, 8.7 nm, 9.0 nm and 9.7 nm using coprecipitation methods then the result was pressed with 50.000N of force to be pellet with diameter of 12.26 mm. The measurement uses computerized impedance spectroscopy in the range of frequency 10 kHz to 120 kHz to investigate its dielectric behaviour toward frequence and grain size changes of CoFe2O4. The result shows that real dielectric constant, imaginary dielectric constant, and loss dielectric increase and tend to constant with the increasing of frequency; impedance increases with the increasing of frequency; although the behaviour has random pattern when considered from their grain size. Overall, in the range of grain size 4.3 < t < 9.7 nm the dielectric constant and dielectric loss increase, and the impedance decreases. Dielectric properties dependence on the crystal structure is also investigated, it is consist of: degree of crystallinity, lattice parameter and the impurities of the sampel. Sample with the best dielectric properties is sample with grain size of 7.7nm and lattice constant of 8.37 ?.

Kata Kunci : CoFe2O4; kopresipitasi; konstanta dielektrik; rugi dielektrik; impedansi; ukuran butir; struktur kristal