Optical constants of float glass, nickel, and carbon from soft-x-ray reflectivity measurements

Angular-dependent reflectivity was measured with a dynamic range of 5-6 orders of magnitude at ~20 different photon energies in the range from 40 to 800 eV with the HASYLAB reflectometer with synchrotron radiation. Several float-glass substrates and a number of sputtered Ni and C films were investigated to improve the accuracy. The optical constants were obtained from least-squares fits of theoretical reflectivity curves, taking into account the influence of film thicknesses and surface and interface roughnesses. All samples with Ni and C films were produced on float-glass substrates, with Ar as the sputter gas, in the low-pressure triode-assisted sputtering facility of the Sincrotrone Trieste.