The 9th International Conference on Surface Engineering (ICSE 2024)

The results of an experimental study of the structural, electrical, magnetic and galvanomagnetic properties of nanostructured layers with a thickness of about 100nm, prepared on the surface of thin (40 µm) films of polyimide (PI) and polyethylene terephthalate (PET) by implantation of 3d-transition metal ions are presented. The layers were obtained by implantation of ions: Ag⁺, Cu⁺, Fe⁺, Co⁺ with an energy of 40 keV in the dose range of 1,25 x10¹⁶ -1,5x10¹⁷ cm^-2 at an ion current density of j=4-12 µA/cm². The patterns of changes in the microhardness and roughness of the modified layer depending on the dose have been established. It is shown, that during implantation of non-magnetic metal ions, the insulator-to-metal transition is not observed. Implantation of magnetic ions leads to a smooth insulator-to-metal transition through the processes of weak localization in the PI(Co) composites at a critical dose of 1,25х10¹⁷ cm^-2 and j=8 µA/cm². A sharp insulator-to-metal transition is observed in PET(Fe) composites at a dose of 1х10¹⁷ cm^-2 and j=4 cm^-2. At room temperature cobalt-based composites are in a superparamagnetic state, while iron-based composites exhibit superparamagnetic and ferromagnetic states depending on the dose. Superparamagenic-ferromagnetic phase transition is observed at a dose of 7,5х10¹⁶ cm^-2. In magnetically ordered layers the magnetoresistive effect is negative. It has sharp and narrow peaks in the range of magnetic fields of 0.1-0.2 T due to spin-dependent scattering of the electrons by domain walls. In layers without magnetic ordering, the magnetoresistance is immeasurable. The correlation of electrical, magnetic and galvanomagnetic characteristics is discussed.
Keywords: ion, implantation, metal-polymer composit, conductivity, magnetization, magnetic state