Isotope Effects Induced by Exterior Actions on the Solid Surface [chapter]

Nikolay N., Yurii I., Vitalii V.
2011 Advances in Composite Materials for Medicine and Nanotechnology  
research technique of mechanisms of a chemical reactions and it is a method of detection of a radicals and radical stages in a chemical process. The magnetic isotopic effect significantly differs by the nature from the usual kinetic isotopic effect related to difference in the isotope masses. In condensed matter the isotope effects are manifested more brightly than in other states of matter. Now the solid-state physics studies influence of isotope effects on elastic, thermal both vibrational
more » ... other properties of crystals. It is installed, for example, that at replacement of hydrogen on a deuterium in the LiH crystal the energies of a electron transitions increase by 2 orders (Plekhanov V.G., 2003) . Now actual problems of isotope engineering are new medium for a data recording, a doping in a semiconductor by a neutron nuclear transmutation, control sensors betterment by ultrapure materials and many other things. Actual problem and major reaching in materials technology is the growing of crystals with the controlled isotope composition. The purpose of the present chapter is a review of the latest work and new experimental data on changes in the isotope composition in the near-surface layers of solids as a result of the secondary ion emission, ion scattering from the surface, ion implantation, electrolytic saturation by hydrogen isotopes, thermo-diffusion from external sources and chemical solution action on the solid surface is presented. Such investigation is needed in materials technology, where atom migration mechanisms and isotope composition changes during various surface interactions occur. The change of isotope composition of the ion beams and near-surface layers of solids has been studied in many works on ion sputtering and secondary ion emission, scattering of ions from surfaces, hydrogen saturation and thermo diffusion from external sources and ion implantation. In all these phenomena, it is very important to identify the basic processes, which determine the change of isotope composition in the near-surface layers of solids. The good understanding of physical mechanisms, which are reviewed here (and of others still unknown mechanisms) will become a basis for the obtaining of the monoisotopic or enriched surfaces with a certain isotopes. It, undoubtedly, will be claimed by future technologies. These investigations are also of the great academic interest as example of nonequilibrium systems. Experimental results and discussion Isotope effects during ion sputtering and the secondary ion emission Slodzian et al were probably the first to study the isotope effect (IE) in secondary ion emission (SIE) (Slodzian et al, 1980 ), although preferential sputtering was noted earlier in 1977 (Lorin et al, 1982 . It was established (Slodzian et al, 1980 ) that in SIE of some minerals, metals, copper oxide, and GaAl alloy produced by oxygen ions, in the energy range 0-20 eV the yield of the light isotope in comparison to the heavy one is greater than the natural isotope ratio. Thus, the enrichment of the sputtered particles by the light ions was found. The degree of enrichment depends on the isotope atomic number, on the matrix containing the isotope in question, and on the ion velocity. Almost at the same time, the space and energy distribution of the SIE isotope rate was studied (Shapiro et al, 1985) . The data (Shapiro et al, 1985) confirmed the results and conclusions (Slodzian et al, 1980) .
doi:10.5772/14013 fatcat:douanil7g5albo5njdnorha3gy