Effect of compressive mechanical stress on the magnetic properties of LiTiZn ferrite ceramics

Abstract In the article, it was experimentally determined that compressive mechanical stress affects the parameters of the temperature dependence of the initial permeability. LiTiZn ferrite ceramics were sintered at 1010/°C for 2/h in air. The experimental curves were mathematically processed using the phenomenological expression to describe the initial magnetic permeability according to the Smith-Wijn model. It is shown that the change in the shape of the experimental curves correlates with the calculated data of the increase in the demagnetizing factor with an increase in mechanical stress. It is hypothesized that the change in the shape of the temperature curves is due to the magnetoelastic effect and the temperature dependence of the magnetostriction constant. Also, it was found that mechanical stress does not affect the X-ray microstructural parameters, including the true physical broadening of the reflexes. At the same time, the growth of mechanical stress to the maximum possible level for such type of ferrite ceramics leads to an increase in the coercive force by 10%. The character of the impact of mechanical stress on the shape of the temperature dependence curve of the initial permeability differs from the effect of non-magnetic Al2O3 additives. Thus the character of the change in the shape of the temperature dependence curve of the initial permeability allows monitoring nonmagnetic phases or mechanical stress in a LiTiZn ferrite ceramics production.