Improved reflectivity of platinum/carbon multilayers for X-ray mirrors by carbon doping into platinum layer
Abstract We present a study of improving the X-ray reflectivity of platinum/carbon multilayers for X-ray mirrors. The X-ray reflectivity of the multilayers depends entirely on the interface quality. Here we show that carbon doping into the platinum layer limits crystallization during deposition and thus reduces the interface roughness. Platinum/carbon and carbon-doped platinum/carbon multilayers were deposited on a silicon (100) substrate by DC magnetron sputtering. The X-ray reflectivity of the multilayers was measured by grazing incidence X-ray reflectometry with a copper K α1 source. We found that the reflectivity increases with the carbon concentration and that an improvement of about 10% in the reflectivity could be expected.
Abstract This research is focused on the effects of nonlinear terms on the dynamical behavior of graphene reinforced laminated composite plates. Firstly, the governing equations of the graphene reinforced composite thin plate subjected to transverse excitations are derived by using the Hamilton's principle and the von Karman deformation theory. Then numerical method is applied to investigate the nonlinear behaviors of graphene reinforced composite plates. Bifurcation diagram, waveform and phase portrait are demonstrated to analyze the nonlinear dynamics of the graphene reinforced laminated composite plates. Furthermore, the effects of nonlinear terms on the dynamical behavior are discussed in detail, where both the stronger and weaker nonlinear characteristics of lower modes of the plate are presented. Moreover, some interesting phenomena are obtained in numerical simulation.