| Texto completo | |
| Autor(es): |
Ensuncho, Laureano
;
Bradtmueller, Henrik
;
Salmon, Philip S.
;
Eckert, Hellmut
Número total de Autores: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of the American Chemical Society; v. 147, n. 34, p. 18-pg., 2025-08-18. |
| Resumo | |
The structural role of Nb2O5 in oxide glasses remains poorly understood, despite the unique linear and nonlinear optical properties that it bestows. Here, advanced solid-state NMR methods can yield valuable insight, but their full potential has been underutilized for niobium-containing systems, especially in respect of the dipolar techniques that provide quantitative information on the interatomic connectivity and distance distributions. This study presents a new NMR-strategy and applies it to the model glass system xNb2O5-(100-x)NaPO3 (0 <= x <= 40). The number of P-O-P linkages per P atom is estimated from the 31P-31P dipole-dipole interactions using spin echo decay (SED) and double-quantum based dipolar recoupling effecting nuclear alignment reduction (DQ-DRENAR). The number of P-O-Nb linkages is obtained from the 31P-93Nb dipolar coupling using 93Nb{31P} rotational echo double resonance (REDOR) and, for the first time, 31P{93Nb} rotational echo saturation pulse double resonance (RESPDOR). Constrained by these interaction-selective experiments, which also include 31P/23Na double resonance spectroscopy, the poorly resolved 31P MAS NMR spectra are quantitatively decomposed into their contributions from the various network-forming units. Additional field dependent 93Nb MAS NMR experiments provide chemical shift parameters that reveal multiple six-coordinate niobium environments with varying degrees of distortion. Overall, the results demonstrate that Nb2O5 assumes a network former role, increasing the overall network connectivity. They also demonstrate an advanced solid-state NMR protocol for characterizing the structural role of Nb2O5, an important intermediate oxide, in multicomponent glasses. (AU) | |
| Processo FAPESP: | 22/14232-0 - Titânio e nióbio: dois elementos importantes, mas enigmáticos na ciência do vidro |
| Beneficiário: | Hellmut Eckert |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| 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 |
| Processo FAPESP: | 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros |
| Beneficiário: | Edgar Dutra Zanotto |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |
| Processo FAPESP: | 22/01937-5 - Incorporação do nióbio em vidros fotônicos: novas relações estruturais/funções descobertas por técnicas avançadas de ressonância magnética |
| Beneficiário: | Laureano Javier Ensuncho Hernández |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |