The effect of externally applied uniaxial compressive stress on the magnetic properties of power MnZn-ferrites

In this article, the effect of uniaxial compressive stress with magnitude up to ~53 MPa on the magnetic properties of power MnZn-ferrites of the general chemical formula Mn 0.81 Zn 0.19 Fe 2+δ Ο 4 has been investigated. In addition, the effects of various process operational or material structural parameters such as sintering partial pressure of oxygen, final density and grain size on the stress sensitivity of the polycrystalline component have been studied. As found, the temperature of the secondary initial permeability maximum and the power loss minimum are reduced by ~0.5 °C MPa −1 while the magnetic flux density by ~1.4 mT MPa −1 upon the exertion of uniaxial compressive stress on the component. The sintering partial pressure of oxygen exhibits an optimum at which the material stress sensitivity becomes minimum. The results have been explained on the basis of variations induced in the anisotropy field as well as on the basis of the defect structure of the material and its dependency on the partial pressure of oxygen.