Quantitative control of magnetic ordering in FeRh thin films using 30 keV Ga ion irradiation from a focused ion beam system

We investigated a low-energy ion-beam irradiation process for the magnetic modification of FeRh thin films using a focused ion beam system. Low-energy ion-beam irradiation induced ferromagnetic states in the FeRh thin films at low temperatures, that originally exhibited antiferromagnetism, as effectively as high-energy ion-beam irradiation. Because the energy deposited by the elastic collisions caused by the irradiation determined the magnetic properties of the samples, the magnetic state of the FeRh thin films could be quantitatively controlled. The low-energy ion-beam irradiation using a focused ion beam system is a potential technique to modify the magnetic properties of materials on the nano- and micro-scales, which may lead to a variety of novel spin devices and applications.