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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

The effect of elastic stresses on the thermodynamic barrier for crystal nucleation

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Abyzov, Alexander S. [1] ; Fokin, Vladimir M. [2, 3] ; Rodrigues, Alisson Mendes [3] ; Zanotto, Edgar D. [3] ; Schmelzer, Juern W. P. [4]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Natl Sci Ctr, Kharkov Inst Phys & Technol, UA-61108 Kharkov - Ukraine
[2] Vavilov State Opt Inst, St Petersburg 193171 - Russia
[3] Univ Fed Sao Carlos, UFSCar, Dept Mat Engn, Vitreous Mat Lab, BR-13565905 Sao Carlos, SP - Brazil
[4] Univ Rostock, Inst Phys, D-18057 Rostock - Germany
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Journal of Non-Crystalline Solids; v. 432, n. B, p. 325-333, JAN 15 2016.
Citações Web of Science: 21

For a variety of oxide glass-forming liquids, the thermodynamic barrier for homogeneous crystal nucleation, W-c, exhibits an unusual increase with a decrease in temperature below the maximum nucleation rate. Such behavior differs from the predictions made using the classical nucleation theory. In this article, we seek possible explanations for the increasing W-c by analyzing whether it is caused by internal elastic stresses that arise due to density misfits between the crystal and liquid phases. For this purpose, crystal nucleation rates and induction time data for two glasses that display significantly different density misfits, lithium and barium disilicates, are employed to determine the work of critical cluster formation. To explain the results, quantitative estimates of the effect of the elastic strain energy on the work required to form a critical nucleus are performed for both glasses. The interplay between stress development and relaxation is accounted for. The computations were performed, taking into account not only the possibility of precipitation of the most stable crystal phase but also that different metastable phases may form during the early stages of nucleation. We show that elastic stresses do indeed reduce the thermodynamic driving force for crystallization, and thus increase the barrier to nucleation. However, the sole effect of elastic strain energy cannot explain the aforementioned unusual behavior of the thermodynamic barrier. Hence, a comprehensive explanation to this phenomenon remains an open issue. (C) 2015 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs