Structure of Fe–Cu alloy layers deposited by IPD method with different frequencies of plasma impulse generation

The aim of the present work was to provide information about the relation between the frequency of impulse plasma generation and a structure of the Fe–Cu alloy layers produced by using the Impulse Plasma Deposition method (IPD). We demonstrate that the frequency of plasma generation constitutes a significant technological parameter, and its variation plays a very important role in the determination of the final morphology of the produced layers. Application of the higher frequency of plasma generation resulted in a change of phase composition and production of more uniform nanostructure. Decrease of roughness from about 10.1 to 6.7 nm and particles size from about 40 to 20 nm was observed. Additionally, we show that differences in the morphology are accompanied by substantial differentiation of the layer nanohardness. Average values of the nanohardness were 2.9 ± 0.6 GPa and 10.8 ± 2.1 GPa, for the layers produced with frequencies of 0.33 Hz and 3 Hz, respectively.