The Preparation and Magnetic Properties of Single-Crystallite of Ba-Ferrite from Ba-Sol Coated <TEX>$delta$</TEX>-FeOOH

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J. Korean Ceram. Soc. > Volume 32(12); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(12): 1383.

Ba-Sol을 도포한 $delta$-FeOOH로부터 Ba-Ferrite 단결정 미리자의 제조와 그 자기적 특성

박영도, 이훈하¹, 이재형², 오영우³, 김태옥

부산대학교 무기재료공학과
¹부사대학교 무기재료공학과
²한국화학시험검사소
³경남대학교 무기재료공학과

The Preparation and Magnetic Properties of Single-Crystallite of Ba-Ferrite from Ba-Sol Coated $delta$-FeOOH

ABSTRACT

Hexagonal $delta$-FeOOH was coated with Ba-Sol, which was produced by hydrolizing Ba(OC2H5)2, Ba-Sol coated $delta$-FeOOH spread on a stainless plate, dried at 8$0^{circ}C$ and then heat-treated. In this way, Ba-ferrite fine particles were produced. although there was a difference in a degree of hydrolysis of Ba(OC2H5)2, crystalline phase of Ba-ferrite appeared around 617$^{circ}C$, and Ba-ferrite single phase was obtained after heat treatment at 80$0^{circ}C$ for 2 hr. When Ba-ferrite was made from Ba-Sol coated $delta$-FeOOH, $delta$-FeOOH was thermally decomposed to $alpha$-Fe2O3 at $700^{circ}C$, producing a porous structure which was observed by TEM photographs. But the porous structure was not observed at 80$0^{circ}C$. Ba-ferrite, heat-treated at 80$0^{circ}C$ for 2 hr, had mean particle size of 1000$AA$, lattice parameter of a0=5.889243 $AA$ and c0=23.214502 $AA$, a saturation magnetization ($sigma$8) of 45.3 emu/g and a coercive force (Hc) of 5200Oe.

Key words: Barium ferrite, $\delta$-FeOOH, Barium ethoxide, Hydrolysis, Barium sol