Dehybridization in RAl2Si2 compounds

1Nikolyuk, PK, 1Yushchenko, AV, 1Stasenko, VA, 1Nikolaichuk, VYa.
1Vinnytsia Regional Branch of the Ukrainian League of Industrialists and Entrepreneurs
Dopov. Nac. akad. nauk Ukr. 2014, 5:83-86
Section: Materials Science
Language: Ukrainian
The theoretical consideration of the dehybridization phenomenon for intermetallic isostructural compounds of the $R\text{Al}_{2}\text{Si}_{2}$ ($R$ – $\rm Sm$, $\rm Eu$, $\rm Gd$, $\rm Tb$, $\rm Er$, $\rm Yb$) row has been performed. The physical nature of the occasion of a $\delta$-like hump, value of which is proportional to the number of lattice sites $N$ formed by $R{-}{\rm Si}$ structural elements, is clarified. In comparison with a single admixture, the value of $\delta$-like hump is more by $N$ times. This is caused by that the orbitals $R{-}{\rm Si}$ play the role of electronic defects, which are periodically located in the frame of the crystal. The performed theoretical and experimental investigations show a great degree of correlation and self-consistency. This gives possibility to view $R{-}{\rm Si}$ bonds as specific electronic defects, which strongly perturb the electronic system of $R{\rm Al}_{2}{\rm Si}_{2}$ compounds. Such perturbation is displayed in arising the intense resonance humps of electronic states, which are formed in the valence zone of the intermetallids under study as a result of the dehybridization factor action.
Keywords: dehybridization, RAl2Si2 compounds

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