Co/Mo2C mirror as studied by x-ray fluorescence and photoelectron spectroscopies induced by x-ray standing waves

We study a periodic Co/Mo2C multilayer prepared by magnetron sputtering. The period is 4.1 nm and the sample is designed to work around 778 eV, i.e. close to the Co 2p3/2 threshold, at a glancing angle of 11°. In this condition, strong x-ray standing waves set up within the sample. In order to probe different depths within the stack, particularly the interfaces, the glancing angle is moved along the first Bragg peak, while, the B 1s, C 1s, Mo 3d or O 1s photoelectron spectra, the Co L? x-ray spectrum as well as the drain current of the sample are measured. Boron is present in the 3.5 nm B4C capping layer and oxygen is from surface contamination. The photoelectrons bring information from the superficial zone, i.e. the 5 first nm, while the characteristic x-rays probe the whole stack. Clear modulations of the intensity of the studied signals as well as core level shifts are observed when going through the Bragg peak. In order to understand what happens in the multilayer calculations of depth distributions of the electric field and the energy loss by the radiation are made with the IMD and OPAL codes, respectively. The combination of experimental results and theoretical simulations will enable us to determine from which place originate the various signals and to know if some interaction exists between the Co and Mo2C layers.