Study of soft x-ray optical properties of niobium carbide (NbC) thin film in 6-15 nm wavelength region

In the present study, the optical constants of niobium carbide (NbC) in soft x-ray wavelength region of 6-15 nm have been determined using angle dependent x-ray reflectivity measurements. Experimentally measured optical constants (δ and β) are compared with tabulated values of Henke et al. The δ values are found 5-30% lower than the bulk value whereas deviation in beta values is around 5-38%. To the best of our knowledge, the present study gives the first reported experimental values of optical constants for niobium carbide in 6-15 nm wavelength range. The knowledge of experimentally measured optical constants of NbC will help in practical calculation of optical devices.