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Second-order optical non-linearity initiated in Li2O-Nb2O5-SiO2 and Li2O-ZnO-Nb2O5-SiO2 glasses by formation of polar and centrosymmetric nano structuresстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Sigaev V.N., Golubev N.V., Stefanovich S.Yu, Komatsu T., Benino Y., Pernice P., Aronne A., Fanelli E., Champagnon B., Califano V., Vouagner D., Konstantinova T.E., Glazunova V.A.
- Журнал: Journal of Non-Crystalline Solids
- Том: 354
- Номер: 10-11
- Год издания: 2008
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 873
- Последняя страница: 881
- DOI: 10.1016/j.jnoncrysol.2007.08.033
- Аннотация: Amorphous nanoheterogeneities of the size less than 100 angstrom have been formed in glasses of the Li2O-Nb2O5-SiO2 (LNS) and Li2O-ZnO-Nb2O5-SiO2 (LZNS) systems at the initial stage of phase separation and examined by transmission electron microscopy, small-angle X-ray and neutron scattering. Both LNS and LZNS nanoheterogeneous glasses exhibit second harmonic generation (SHG) even when they are characterized by fully amorphous X-ray diffraction (XRD) patterns. Chemical differentiation and ordering of glass structure during heat treatments at appropriate temperatures higher T-g lead to drastic increase of SHG efficiency of LNS glasses contrary to LZNS ones in the frame of amorphous state of samples. Following heat treatments of nanostructured glasses result in crystallization of ferroelectric LiNbO3 and non-polar LiZnNbO4 in the LNS and LZNS glasses, respectively. Taking into account similar polarizability of atoms in LNS and LZNS glasses, the origin of the principal difference in the second-order optical non-linearity of amorphous LNS and LZNS samples is proposed to connect predominantly with the internal structure of formed nanoheterogeneities and with their polarity. Most probably, amorphous nanoheterogencities in glasses may be characterized with crystal-like structure of polar (LiNbO3) phase initiating remarkable SHG efficiency or non-polar (LiZnNbO4) phase, which do not initiate SHG activity. It gives an opportunity to vary SHG efficiency of glasses in a wide rage without remarkable change of their transparency by chemical differentiation process at the initial stage of phase separation when growth of nanoheterogeneities is 'frozen'. At higher temperatures, LiNbO3 crystals identified by XRD precipitate in LNS glasses initiating even more increase of SHG efficiency but visually observable transparency is impaired. (C) 2007 Elsevier B.V. All rights reserved.
- Добавил в систему: Стефанович Сергей Юрьевич