Effect of oxidation degree on electromagnetic properties of Mn-Zn ferrite

The effect of oxygen partial pressure during sintering process on the elect romagnetic properties of Mn-Zn ferrites has been studied. Equilibrium oxyge n partial pressure was precisely controlled according to log Po-2 = A - 145 40/T(K). At low oxygen partial pressure, significant Zn volatilization as w ell as loss of oxygen was observed, As the oxygen parameter (A) decreased f rom 8.2 to 7.6, the power loss minimum and the second maximum of initial pe rmeability moved to lower temperatures. These shifts were not clearly obser ved with oxygen parameters below 7.6. The core sintered at A=7.0 showed the prominent second permeability peak.