Инд. авторы:	Adichtchev S.V., Malinovsky V.K., Ignatieva L.N., Merkulov E.B., Surovtsev N.V.
Заглавие:	Low-frequency inelastic light scattering in a ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass
Библ. ссылка:	Adichtchev S.V., Malinovsky V.K., Ignatieva L.N., Merkulov E.B., Surovtsev N.V. Low-frequency inelastic light scattering in a ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass // Journal of Chemical Physics. - 2014. - Vol.140. - Iss. 18. - Art.184508. - ISSN 0021-9606. - EISSN 1089-7690.
Внешние системы:	DOI: 10.1063/1.4875095; PubMed: 24832289; WoS: 000336782700090;
Реферат:	eng: Low-frequency (down to 30 GHz) inelastic light scattering is studied in a multicomponent glass ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) in a wide temperature range. The contributions of the THz vibrational spectrum (boson peak) and of the fast relaxation are extracted and analyzed. It is shown that the fast relaxation spectrum is described by a distribution of relaxation times leading to a power-law v(alpha) dependence in the frequency range 30-300 GHz. Temperature dependence of alpha(T) is well described by the Gilroy-Phillips model, while the integrated intensity of the fast relaxation increases significantly with the temperature. This feature distinguishes the fast relaxation in ZBLAN from the case of most single-component glasses. Thermodynamic and kinetic fragility indexes are significantly different for the ZBLAN glass. The correlations between the boson peak intensity, elastic moduli, and fragility index, found earlier for single-component glasses, are fulfilled for the thermodynamic fragility index of ZBLAN. In contrast, the correlation between the fast relaxation intensity at T-g and the fragility holds better for the kinetic fragility index of ZBLAN. We propose that thermodynamic and kinetic fragilities reflect different aspects of glassy dynamics in the case of glass formers with the complex chemical composition and structure topology: the former correlates with the elastic properties and the boson peak, the latter with the relaxation. (C) 2014 AIP Publishing LLC.
Ключевые слова:	COUPLING COEFFICIENT; VITREOUS SILICA; NEUTRON-SCATTERING; BOSON PEAK; BRILLOUIN-SCATTERING; FAST RELAXATION; RAMAN-SCATTERING; MEDIUM-RANGE ORDER; FLUORIDE GLASSES; VIBRATIONAL DYNAMICS;
Издано:	2014
Физ. характеристика:	184508