용융염법으로 합성한 Ba-ferrite 입자의 특성

Properties of ba-ferrite Particles Synthesized by Molten Salt Method

In order to synthesize Ba-ferrite particles by molten salt method KCl and NaCl were added to basic composition to 50% by weight. X was varied from 0.0 to 1.0 to control the magnetic properties in $BaFe_{12-2x}$/ $Co_{x}$ / $Ti_{x}$ / $O_{19}$ and 1 mol% of $SiO_2$was added to control the aspect ratio of hexagonal platelets. And the effects of reaction temperatures were examined by varying the temperature from 85$0^{\circ}C$ to 120$0^{\circ}C$ with 5$0^{\circ}C$ intervals. Eutectic composition of NaCl and KCl lowered the crystallizing temperature of Ba-ferrite in molten salts than using KCl and NaCl separatly. The morphology of resulting Ba-ferrite particles was clearly hexagonal-shaped plates. $H_{c}$ and $M_{r}$ were decreased when F $e^{3+}$ was substitued with $Co^{2+}$ and $Ti^{4+}$ from x=0 to x=1.0 in $BaFe_{12-2x}$/ $Co_{x}$ / $Ti_{x}$ / $O_{19}$ . Adding 1mol% $SiO_2$in molten salt method increased the size but shortened c-axis of the hexagonal ferrites and this result is an opposite phenomenon compared with the result in solid-statge reaction.n.ion.n.