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Materials Congress 2018
Page 86
Nano Research & Applications
ISSN: 2471-9838
W o r l d C o n g r e s s o n
Materials Science & Engineering
A u g u s t 2 3 - 2 5 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
Over of last five decades a great number of stable isotopes and well – developed method of their separation has made it
possible to date to grow crystals of C, LiH, ZnO, ZnSE, CuCl, GaN, GaAs, CdS, Cu2O, Si, Ge, α-Sn as well as graphene with
a controllable isotopic composition. The use of such objects allows the investigate of not only the isotope effects in diffusion
and lattice dynamics (vibrational, elastic and thermal properties) but also the influence of such effects on the electronic states
via electron – phonon coupling (the renormalization of the band – to – band transition energy Eg as well as the exciton binding
energy Eb). The thermal conductivity enhancement in the isotopically enriched materials amounts (C, Ge, SI) to almost 10% at
room temperature and is close to a factor of six at the thermal conductivity maximum around 20K (Si-case). The change in the
lattice constant is Δa/a ~ 10-3- 10-4, while the change Δcik in the elastic constants amounts to several percent. Very pronounced
and general effects of isotope substitution are observed in phonon spectra. The scattering lines in isotopically mixed crystals are
not only shifted (the shift of LO lines exceeds 100 cm-1) but are also broadened. Capture the thermal neutrons by isotope nuclei
followed by nuclei decay produces new elements in a very large number of possibilities for isotope selective doping of different
materials. Although the technology of isotopic materials science is still in its infancy, it is necessary underline that it has very
wide applications: beginning from optical fiber technology still modern development in isotope information storage and isotope
quantum computers.
Some peculiarities of isotopic materials science
V G Plekhanov
Fonoriton Sci Lab, Estonia
Nano Res Appl 2018, Volume: 4
DOI: 10.21767/2471-9838-C4-018