Manufacture of w-phase type hexagonal ferrite particles

Abstract

Abstract PURPOSE:To obtain the titled particles having a favorable particle size and high dispersibility and easy to orient in a magnetic field by causing coprecipitation in a mixed aqueous soln. contg. specified two kinds of salts and an iron salt in the presence of an alkali or an oxalate and by separating and calcining the resulting precipitate. CONSTITUTION:Coprecipitation is caused in a mixed aqueous soln. contg. a salt of R<2+> (R is Ba, Sr, Pb or Ca), a salt of Me<2+> (Me is Ni, Co, Cu, Cd, Zn, Mg or Fe) and a ferrous salt and/or a ferric salt in the presence of an alkali or an oxalate, and the resulting precipitate is separated, washed, taken out by filtration, dried, and calcined to manufacture ferrite particles having a single W phase or a composite phase contg. a W phase. By this wet process the titled particles having a particle size in a favorable range and easy to orient in a magnetic field are obtd. The particles have higher dispersibility than particles obtd. by a conventional dry process and they are easily separated from water. The precipitate is practically free from alkali, etc.

Inventors

• 👤 Hiroshi Kojima
• 👤 浩 小島
• 👤 Choji Miyagawa
• 👤 宮川　長二
• 👤 Takafumi Sato
• 👤 隆文 佐藤
• 👤 Shigeo Niitsuma
• 👤 新妻　茂雄

Bibliographic Details