Search academic texts

Registration Number

0224U031469, 0122U001969 , R & D reports

Title

Interfaces in heterostructural nanocomposites: theoretical modeling and experimental studies of electronic and optical processes

Head

Khyzhnyi Yurii A., Доктор фізико-математичних наук

Registration Date

30-04-2024

Organization

Taras Shevchenko National University of Kyiv

Description

Results of theoretical calculations of atomic and electronic structure, optical constants, optical spectra and conductivity of interface layers of nanocomposites of selected types were obtained. Using the methods of molecular dynamics and electronic structure, theoretical modeling of the atomic structure, electronic properties, and optical spectra of nanocomposite materials (glass ceramics) of different composition and structure was carried out, in particular "KBi(MoO4)2 crystal / phosphate-molybdate glass", " K2Eu(PO4)(WO4) crystal / phosphate-tungstate glass" and "LaVO4 crystal / borate glass". The structure of the nearest oxygen surrounding of bismuth atoms in phosphate-molybdate glass-ceramics was analyzed using the results of atomic structure calculations. The analysis provided an explanation for the experimentally observed changes in the spectral characteristics of luminescence of Eu3+ impurity ions, which replace bismuth atoms in the investigated glass-ceramic samples. Results of calculations of the energies of the excited electronic states of particular atoms, ions and molecular fragments of the interface regions, which can be the centers of luminescence of the studied nanocomposite materials, were obtained. To explain formation of the experimentally observed properties of bismuth-containing glass-ceramics, theoretical calculations of the optical spectra by the time-dependent density functional theory (TD-DFT) method were carried out for bismuth atoms and molybdate groups located in different spatial regions of glass ceramics "KBi(MoO4)2 crystal / phosphate-molybdate glass" and can form the centers of luminescence of this material. Experimental characteristics of electrical conductivity, optical absorption/reflection and luminescence spectra were obtained for nanocomposite materials, the interfaces of which were investigated by computational methods.

Product Description

popup.authors

Borysiuk Viktor I.
Nedilko Serhii H.
Teselko Petro O.
Chornii Vitalii Р.
Chukova Oksana V.
Svintsitskyi Vasyl P.
Yashchuk Vasyl P.