XANES and XPS studies of processes initiated by high-vacuum annealing in Sn[O.sub.x]/MWCNT composite layers

The initial and thermally treated composites based on Sn[O.sub.x]/MWCNT have been studied by the XANES and XPS methods using the equipment of the BESSY II Russian--German beamline of synchrotron radiation and by the AES and HRTEM methods. The characteristic mechanisms of chemical and structural transformations in the Sn[O.sub.x] phase have been determined depending on the vacuum annealing temperature. It has been found that the basic process in the metal-oxide component at annealing temperatures not exceeding 500°C is the tin monoxide SnO disproportionation reaction with the formation of the dioxide Sn[O.sub.2] phase and metallic tin. An increase in the annealing temperature to 800°C results in the activation of carbothermal reduction of metallic tin in contact areas of oxide clusters and MWCNT, as well as in the formation of nanocrystalline structures in the metal-oxide component of composite.