Magnetic properties of thin metal-polymer films prepared by high-dose ion-beam implantation of iron and cobalt ions into polyethylene terephthalate

Thin metal-polymer composite films have been prepared by high-dose ion-beam implantation of Fe(+) and Co(+) ions into polyethylene terephthalate. The implantation of 40 keV ions at room temperature with doses from 2 center dot 10(16) to 4 center dot 10(17) cm(-2) have been performed, with the ion current density of 4 mu A/cm(2). The effects of implantation dose on the film morphology and crystal structure have been investigated via atomic force and magnetic force microscopy and X-ray diffraction. The magnetic properties of synthesized structures have been studied by ferromagnetic resonance and with a vibrating-sample magnetometer. It was established that the properties of ion-implanted samples strongly depend on both the implantation dose and the type of implanted ions. The implantation dose at which the magnetic phase is formed for iron-implanted samples is significantly lower than that for cobalt-implanted ones. At high implantation doses due to polymer sputtering metal-containing layers are formed close to the sample surface for both ions. In this dose range the magnetic properties of implanted samples changed dramatically due to particle oxidation. The coercivity of synthesized layers reaches 180 and 300 Oe for iron- and cobalt-implanted samples, respectively.