Ion Irradiation Effects on the Crystal Structure and Magnetic Properties of Iron–Nickel Binary Alloys

Iron-based alloys are widely used in the structural components of fission and fusion reactors. Since the change in magnetic properties during neutron irradiation can cause harmful effects on the components, the irradiation effects on magnetism and their mechanisms merit attention. This study focuses on the role of structural and magnetic phase stabilities and investigates the effects of ion irradiation on the magnetic properties of Fe–
$x$
%Ni (
$x$
= 16, 24, 29, and 36) films. After 2.4 MeV Cu
$^{2+}$
irradiation up to 0.9 displacements per atom (dpa), an increase in saturation magnetization occurs in face-centered cubic (FCC) Fe–29%Ni film, but almost no effects appear in the other specimens. This relates to the structural and the magnetic instabilities of the alloys.