Mechanical properties of the X-ray irradiated DLC films containing SiOx as a constructive element for radiation detectors

Evolution of physical properties and radiation-induced changes of the film composition and chemical bonding structure have been investigated in ion beam deposited and SiOx-containing DLC films after their exposure to high-energy X-ray photons generated in medical linear accelerator aiming the possible use of these films as protective coatings or passive layers in the construction of radiation detectors. Mechanical properties of the irradiated films were characterized by microhardness measurements and atomic force microscopy and were analyzed in parallel with the optical properties of the investigated samples. Chemical bonding structure of the DLC films was estimated by Raman spectroscopy (RS). Atomic composition of the films was evaluated from the X-ray photoelectron spectroscopy (XPS) measurements. Changes in surface morphology and increased hardness of the investigated samples as compared to the initial samples were observed. Comparing the results of investigation of SiOx-containing DLC films with those obtained for undoped hydrogenated DLC films, it was possible to figure out the relationship between radiation-induced structural changes and modification of the properties of different DLC films during irradiation by high-energy X-ray photons. (c) 2008 Elsevier B.V. All rights reserved.