STUDI PENGARUH STRUKTUR KRISTAL DAN UKURAN BUTIR PARTIKEL TERHADAP SIFAT DIELEKTRIK NANOPARTIKEL MAGNESIUM FERRITE (MgFe2O4); STUDY ON THE INFLUENCE OF CRYSTAL STRUCTURE AND GRAIN SIZE ON DIELECTRIC PROPERTIES OF MAGNESIUM FERRITE (MgFe2O4) NANOPARTICLES

Dirgantara, Arya, Edi Suharyadi

2015 | Disertasi | FMIPA

Magnesium Ferrite (MgFe2O4) has been synthesized with result size of particles of 2.1 nm, 6.4 nm, 6.5 nm, 7.8 nm, and 10.7 nm by using co-precipitation methods then the result was pressed to be pellets. The dielectric permittivity determining is applied by using computerized impedance spectroscopy system in the range of input frequency 10-120 kHz. The result shows that real dielectric permittivity (??), imaginary dielectric permittivity (?”), and loss dielectric (tan ?) decreases and tend to constant (~80 kHz) by the increasing of frequency, impedance (Z) increases by the increasing of frequency. The 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. Overall, in the range of grain size 2.1-10.7 nm the real dielectric permittivity (??), imaginary dielectric permittivity (?”), and loss tangent decreases with increasing grain size. Sample with the best dielectric properties is sample with grain size of 10.7 nm with real dielectric permittivity 499.5; imaginary 363.1; loss tangent 0.7; and impedance 137.4 k? on frequency 10 kHz. The result of dielectric permittivity determining suits theory.

Kata Kunci : MgFe2O4 nanoparticles; dielectric permittivity; grain size; and crystal structure.