Investigating the structural changes induced by SHI on WSiC samples.

Abstract

The structural modification of tungsten-SiC samples irradiated with Xe26þ swift heavy ions (SHIs) was investigated. Tungsten (W) thin films were deposited on 6H–SiC using e-beam. After deposition, the W–SiC samples were irradiated by 167 MeV Xe26þ ions to fluences of 1012 cm 2, 1013 cm 2 and 1014 cm 2 at room temperature. The sample composition, phase identification, residual stress component and surface morphology were investigated with Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-deposited samples were composed of W and SiC, with no reaction between them. The samples irradiated to a fluence of 1012 cm 2 showed that a reaction between W and SiC took place resulting in the formation of WSi2 and WC phases. The samples irradiated to fluences of 1013 and 1014 cm 2 showed further reactions between W and SiC with WSi2 and WC being the only phases formed. The SiC substrate had bi-axial compressive stress which did not excess 700 MPa after irradiating to the highest fluence. The W layer deposited on SiC was flat and homogeneous after deposition. A textured surface with identifiable grains was observed after the SHI irradiations. Keywords: Tungsten, Thin film, SiC, SHIs, Irradiation, Reaction