Abstract
Hexagonal M-type barium ferrite $BaFe_{12}O_{19}$ was prepared by a direct solid state reaction between $BaCO_3$ and ${\Alpha}-Fe_2O_3$ powders at temperatures ranging from 800 to 1000 $^{\circ}C$ in a nitrogen or air environment. The effects of NaCl on phase transformation of mixture of $BaCO_3$ and ${\Alpha}-Fe_2O_3$ to $BaFe_{12}O_{19}$ were studied using X-ray diffraction and M$\"{o}$ssbauer spectroscopy. Regardless of the environment for heat treatment or the added NaCl, two phases, BaFe and ${\Alpha}-Fe_2O_3$, coexist for samples heat treated at 800 $^{\circ}C$, but a single phase was observed from samples heat treated at 100$0^{\circ}C$ in both air and nitrogen environments. It was found that the addition of NaCl reduced the amount of $a-Fe_2O_3$ phase.hase.
육방구조의 M형 BaFe12O19를 NaCl를 첨가한 경우와 첨가하지 않은 경우에 질소가스 분위기와 공기 중에서 여러 온도로 가열하여 고상반응법으로 제조하였다. X-선 회절법과 Mossbauer분광법에 의하여 BaFe12O19상과 $\alpha$-Fe2O3상의 공존 정도를 알아냈다. 동일한 조건에서 NaCl를 첨가한 경우가 NaCl를 첨가하지 않은 경우 보다 $\alpha$-Fe2O3상이 적음을 확인하였다.
