Recovery of ion-beam treatment (IBT) is perspective directions of improvement of materials properties. Before authors showed, that IBT under certain conditions influences on magnetic properties of soft magnetic materials (SMM). Thermomagnetic treatment (TMT) is used for increase of functional properties of SMM traditionally.

Combining IBT and TMT is of interest.

It is found that the electromagnetic loss (P) in the Fe-3%Si alloy is reduced by 10% after IBT+TMT, the magnetostriction remains unchanged. But the magnetostriction increases from 1.5·10⁶ to 16.0·10⁶ and Р_0.7/1000 grows from 12.8 to 31 W/kg (but it is a permissible level) after TMT+IBT.

A reason why IBT reduces P is the fact that IBT leads to a considerable increase in the low-temperature mobility of atoms; and it facilitates a refinement of the alloy volumes in vibration zones of magnetic domain boundaries during TMT. In volumes, which are free of defects, the magnetic domain structure becomes more destabilized.

IBT increases the defects content of an alloy after TMT. As a result, compression stresses appear in the surface layer, and, correspondingly, tensile stresses appear in the rest of the volume. Compression stresses cause a change in the magnetic domain structure; namely, a system of small domains with transverse magnetization appears. It provides the maximum magnetostriction deformations of the sample at its magnetic reversal during operation and tensile stresses give magnetic softness.

Thus, application of IBT allows to operate properties of materials over a wide range.

This work was partially supported by RFBR (grant 08-02-00327) and an integration project IMP–IEP UD RAS 09-И-2-2002.