Tdk Corporation

Shenglei Che

Kentaro Mori

Takuya Aoki

Tomofumi Kuroda

Masahiko Watanabe

Tomohiro Sogabe

Shigeo Okamoto

Ikuka Chiba

Provided is a process for producing a MnZn-base ferrite comprising: firing a compacted raw material to produce the MnZn-base ferrite, wherein the firing comprises, in the following order: a heating phase comprising gradually bringing a firing temperature from room temperature up to a maximum temperature; a maximum temperature holding phase comprising maintaining the maximum temperature for a period of time, wherein a partial pressure of oxygen (p2) at the maximum temperature holding phase is greater than an equilibrium partial pressure of oxygen (p1) as follows: p2&#x3e;p1, wherein the equilibrium partial pressure of oxygen (p1) is represented by the following equation: log(p1)=log(PO)=a&#x2212;b/T, wherein POis measured in a unit of %, and T is measured in a unit of absolute temperature K; and a cooling phase comprising gradually bringing the maximum temperature down to near room temperature, wherein a partial pressure of oxygen (p3) at the cooling phase is operated at an equilibrium partial pressure of oxygen based on the equation log(p3)=a&#x2212;b/T.

Method of producing MnZn-base ferrite

The present invention provides a production method of spherical oxide powder which includes a feeding step in which a granular powder composed of an oxide composition is fed into a combustion flame together with a carrier gas; a melting step in which said fed granular powder is melted in said combustion flame to obtain a melt; and a solidifying step in which said melt is solidified by being moved and placed outside said combustion flame.

Method of producing spherical oxide powder

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Tokyo, Japan

Shenglei Che