MnZn-ferrites: Targeted Material Design for New Emerging Application Products
Abstract.In this article the main characteristics for emerging MnZn-ferrite applications are described on the basis of the new demands they possess on the ferrite material development. A number of recently developed MnZn-ferrite materials is presented together with the main scientific principles lying behind their development. These include: (i) high saturation flux density MnZn-ferrites (i.e. Bsat=550 mT at 10 kHz, 1200 A/m, 100oC), (ii) low power losses MnZn-ferrites (i.e. Pv~210 mW cm-3 at 100 kHz, 200mT, 100oC), (iii) MnZn-ferrites with broad temperature stability (i.e. PV<375 mW cm-3 for 25oC<T<140oC at 100 kHz, 200 mT), and (iv) MnZn-ferrites with high and frequency stable permeability (i.e. μi~12600 at 10 kHz, 0.1 mT, 25oC and tan(δ)/μi=20.5x10-6 at 100 kHz). In a final discussion the importance of defect chemistry for the time stability and stress sensitivity of the magnetic properties is discussed and some important issues are addressed, encountered during the transfer of a laboratory developed material to a large scale industrial production process.