| Abstrak/Abstract |
Zn-Ni ferrite nanoparticles were successfully synthesized by coprecipitation method. The samples
were annealed at various temperatures, i.e., 200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C. The
nanoparticles have the mixed spinel phase structure as confirmed by the X-ray diffraction patterns.
The crystallite size was 15.1 nm and increased to 25.1 nm after annealing at 1000 °C. Transmission
electron microscope images showed that the annealed sample exhibited better dispersion and grain
boundaries compared to the as-prepared sample. Fourier transform infra-red spectra showed the
existence of vibrations at 378 cm?1 and 555 cm?1
, confirming bonding for mixed spinel ferrites. The
hysteresis measurement by using vibrating sample magnetometer confirmed that the sample
possessed soft magnetic properties with a coercivity of 45 Oe and increased after annealing. The
saturation magnetization of the as-prepared sample was 11 emu g?1
, and increased to 58 emu g?1
after annealing at a temperature of 800 and 1000 °C. The specific absorption rate (SAR)with an
alternating current magnetic field (50 Hz and 100 Oe) of Zn-Ni ferrite before and after annealing (at
800 °C)was 63.7 and 92.4 mW g?1
, respectively. The results showed that annealing temperature has a
significant role in determining the microstructural, the magnetic properties and the SAR of the
nanoparticles. |
