The Microstructural Study of Swift Heavy 75MeV Oxygen-ion and 100MeV Ag-ion Irradiated PVDF Thin Films by Atomic Force Microscopy

摘要

Polyvinylidene fluoride (PVDF) polymer films of different thicknesses are irradiated with 100 MeV Ag-ion, 75 MeV Oxygen- ion beams at different fluences to study the swift heavy ion (SHI) irradiation effects on the surface of thin films. The surface topography, structure and surface mechanical properties of pristine and irradiated films are investigated by means of Atomic force microscopy (AFM) in trapping mode. AFM operation in trapping mode is preferred for high resolution topographic image of surface and to avoid damage to the tip and sample surface. The AFM micrographs of pristine and irradiated PVDF samples show small granular microstructure. AFM morphological characterizations of irradiated films reveal the formation of nano sized crater and hillocks on the surface. The AFM is also used to estimate average surface roughness, hardness, grain size, grain density entropy and other structural parameters. It is observed that the average surface roughness and grain size is decreases upon ion irradiation and the decrease is dependent on the nature of ion beam and its energy and fluences. An inverse Hall-Petch effect has been observed for PVDF thin films upon ion beam irradiation i.e., decrease in hardness of PVDF films upon ion beam irradiation.