Effect of 50-keV proton irradiation on the magnetism of a Fe66Ni34 Invar alloy

The magnetism of Fe–Ni Invar alloys is very sensitive to the lattice constant, stress, and the number of nearest-neighbor Fe–Fe atomic pairs. Ion irradiation is a useful tool to alter the local atomic structure of a given material. Therefore, the effects of low-energy and light-ion irradiation on the magnetism of a Fe66Ni34 Invar alloy were investigated in this study. The Fe66Ni34 Invar alloy was irradiated with 50-keV protons at a fluence of 1×1015 ions/cm2 at room temperature. The Curie temperature was found to increase from 465 K (before irradiation) to 535 K (after irradiation). The X-ray absorption analysis of the fine structure of the alloy revealed that irradiation had no effect on the atomic structures surrounding Fe and Ni.

► Low energy and light ion beam irradiation effect on Fe–Ni Invar have been investigated.
► 50 keV proton ion of fluence 1×1015 irradiated to the Fe66Ni34.
► Curie temperature of Fe66Ni34 increased from 465 K to 535 K due to irradiation.
► Structural change was not confirmed by 50 keV proton irradiation.