Network former mixing effects in alkali germanotellurite glasses: A vibrational spectroscopic study

Autor(es)

Tagiara, N. S. ^[1] ; Chatzipanagis, I, K. ; Bradtmueller, H. ^{[2, 3]} ; Rodrigues, A. C. M. ^[3] ; Moncke, D. ^[4] ; Kamitsos, I, E.

Afiliação do(s) autor(es)

^[1] I, Natl Hellen Res Fdn, Theoret & Phys Chem Inst, 48 Vassileos Constantinou Ave, Athens 11635 - Greece

^[2] Westfalische Wilhelms Univ, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany

^[3] Univ Fed Sao Carlos, Dept Mat Engn, Vitreous Mat Lab, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[4] Alfred Univ, Inamori Sch Engn, New York State Coll Ceram, 1 Saxon Dr, Alfred, NY 14802 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Alloys and Compounds; v. 882, NOV 15 2021.
• Citações Web of Science: 0

Resumo

Alkali germanotellurite glasses of composition 0.3M(2)O-0.7{[}(1-x)GeO2-xTeO(2)], M=Li, Na and 0 <= x <= 1, were investigated by Raman and infrared vibrational spectroscopic techniques to search for the origins of the alkali ion-dependent network former mixing (NFM) effect in these ion-conducting glasses. The vibrational spectra measured on mixed network-former glasses, and the spectral comparison between equimolar-mixed glasses (x = 0.5) and pellet-mixtures of the endmember glasses, 0.3M(2)O-0.7GeO(2) and 0.3M(2)O-0.7TeO(2), provided evidence for the formation of hetero-atomic Ge-O-Te linkages and structural rearrangements in the germanate and tellurite components of the glass. The mixing-induced structural rearrangements were expressed in terms of chemical equilibria between the network-building units and were used to make qualitative predictions for changes in the network cross-linking density and the related network-strain energy, as well as in the binding energy part of the activation energy for ion conduction. Thus, it is proposed that the mixing-induced structural modifications in the germanate and tellurite parts of glass cause the cancelation of changes in the binding energy and the network-strain energy contributions to the activation energy for ion transport. These qualitative predictions were discussed in the context of the previously found absence of an NFM effect in ionic conductivity for M=Na and the presence of a weak positive NFM effect for M=Li. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 17/02953-6 - Estudos estruturais de vidros fosfatos iônicos, dopados com metais de transição para aplicação elétrica e de óptica não linear
• Beneficiário: Ana Candida Martins Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 19/26399-3 - Elucidação de rearranjos estruturais durante o processo de relaxação e cristalização de materiais vítreos
• Beneficiário: Henrik Bradtmüller
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado