MANUFACTURING METHOD OF MnZn FERRITE HAVING HIGH MAGNETIC PERMEABILITY

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a MnZn ferrite having high magnetic permeability which achieves high initial magnetic permeability and high specific resistance simultaneously and has a high impedance characteristic.;SOLUTION: A manufacturing method of a MnZn ferrite having high magnetic permeability which achieves high initial magnetic permeability and high specific resistance simultaneously and has a high impedance characteristic can be obtained by setting the temperature-rising rate during the temperature-rising process from 500°C to the holding temperature at 350°C/hr or higher and setting the oxygen concentration during the temperature-rising process at 10,000 ppm by volume or less in the sintering process of MnZn ferrite having high magnetic permeability, wherein the oxygen concentration at the holding temperature is divided into 2 stages, the holding oxygen concentration at the first stage is set at 20 vol% or more, the holding oxygen concentration at the second stage is set at 5 vol% or more and 30 vol% or less, the holding time at the first stage is set at 2 hr or longer and 20 hr or shorter and the holding time at the second stage is set at 1 hr or longer and 4 hr or shorter, and the oxygen concentration during cooling process is defined by a function of oxygen concentration PO₂ and temperature T expressed by log(PO₂)=-A/T+B, wherein A in the function is set at 8,000 or larger and 18,000 or smaller.;COPYRIGHT: (C)2009,JPO&INPIT