Production of particulate powder of lamellate ba ferrite for magnetic recording

Abstract

Abstract PURPOSE:To obtain the particulate powder of lamellate Ba ferrite having suitable coercive force and large magnetization value by heating and calcining the particles of lamellate Ba ferrite deposited with zinc hydroxide on the surfaces of the particles under the presence of flux. CONSTITUTION:The fine particles of lamellate Ba ferrite deposited with zinc hydroxide on the surfaces of the particles are obtained by suspending the fine particles of lamellate Ba ferrite in an aq. soln. contg. zinc having 4.0-12.0 pH. Then after filtering and drying the fine particles, these are heated and calcined under the presence of flux at the temp. not less than m.p. of this flux. Thereafter the heated and calcined material is washed to remove the flux. As the above-mentioned aq. soln. contg. zinc, the aq. soln. of halide such as zinc chloride, zinc bromide, zinc iodide and zinc nitrate, zinc sulfate and zinc acetate, etc., can be used. Further as the flux, one or two and more kinds of halide and sulfate, etc., of alkali metal and alkaline earth metal can be used and NaCl, BaCl2 and KCl, etc., are preferable from a point of the enhancement of magnetization value and economicity.

Inventors

• 👤 Norimichi Nagai
• 👤 規道 永井
• 👤 Tsutomu Katamoto
• 👤 勉 片元
• 👤 Akihiko Hirayama
• 👤 平山　彰彦
• 👤 Masao Kiyama
• 👤 木山　雅雄
• 👤 Toshio Takada
• 👤 高田　利夫

Bibliographic Details