Effect of stresses on the magnetostriction of Ni-Zn(Co) ferrites

Magnetostrictive Properties and Magnetoelastic Villari Effect in the High-permeability Mn-Zn Ferrites

“…Significant magnetoelastic Villari effect was observed in spite of low magnetostriction of this ferrite. Probably this phenomenon is connected with the fact that also magnetostriction of this ferrite changes under the influence of the stresses [5]. As a result, material with nearly zero magnetostriction (magnetostriction measured without stresses) may be stress-sensitive.…”

Experimental determination of magnetocrystalline anisotropy constants and saturation magnetostriction constants of NiZn and NiZnCo ferrites intended to be used for antennas miniaturization

“…The stress-induced changes in permeability may include magnetoelastic anisotropy constant K σ . In the case of isotropic magnetostriction, K σ is given [18,20,[41][42][43] by 3/ 2 Â λ S Âσ i , where λ S is the magnetostriction constant and σ i is the local stress on the grains (correlated with the molding pressure P). The effects of magnetocrystalline and magnetoelastic anisotropies are then described in terms of two anisotropy fields H K and H σ , so the effective anisotropy field H e is written H e ¼H K þH σ .…”

Stress-Induced Anisotropy and Stress Dependence of Saturation Magnetostriction in the Jiles-Atherton-Sablik Model of the Magnetoelastic Villari Effect

“…For higher values of compressive stresses, saturation magnetostriction ls of the Mn 0.51 zn 0.44 Fe 2.05 O 4 ferrite is positive. The phenomenon of sign change of magnetostriction was previously observed experimentally [20], but was never modelled quantitatively. Moreover, the extrapolated value of saturation magnetostriction 0.1 mm/m for unstressed material is in accordance with typical values measured experimentally for high-permeability Mn-zn ferrites.…”

“…Filling this gap will create possibility of more accurate modelling of influence of mechanical stresses on the shape of magnetic hysteresis loop. Moreover, it will create possibility of numerical determination of experimentally observed [20] changes of saturation magnetostriction λ s of magnetic material subjected to mechanical stresses σ.…”