The effects of stress on some properties of MnZn ferrite

The effects of tensile and compressive stresses applied parallel to the magnetic flux path were observed on specially shaped specimens cut from blocks of low-loss MnZn ferrous ferrite typical of those used for inductor cores. The permeability, losses and coercivity were observed as functions of temperature. Stress levels of about one tenth of the ultimate tensile strength resulted in a significant increase in losses and a pronounced effect on the permeability-temperature curve. The latter effect is generally consistent with the known variation of anisotropy and magnetostriction with temperature.