Structure of amorphous materials in the NASICON system Na 1+x Ti2Si x P 3-x O-12

Autor(es)

Da Silva, Rita Mendes ; Zeidler, Anita ; Bradtmuller, Henrik ; Eckert, Hellmut ; Fischer, Henry E. ; Benmore, Chris J. ; Salmon, Philip S.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 35, n. 27, p. 9-pg., 2023-07-12.

Resumo

The structure of glasses in the sodium (Na) super-ionic conductor (NASICON) system Na 1+x x P 3-x x = 0.8 and x = 1.0 was explored by combining neutron and high-energy x-ray diffraction with Si-29, P-31 and Na-23 solid-state nuclear magnetic resonance (NMR) spectroscopy. The Si-29 magic angle spinning (MAS) NMR spectra reveal that the silica component remains fully polymerized in the form of Si-4 units, i.e. the silicon atoms are bound to four bridging oxygen atoms. The P-31{Na-23} rotational echo adiabatic passage double resonance (REAPDOR) NMR data suggest that the P-31 MAS NMR line shape originates from four-coordinated P- n units, where n = 1, 2 or 3 is the number of bridging oxygen atoms per phosphorus atom. These sites differ in their P-31-Na-23 dipolar coupling strengths. The results support an intermediate range order scenario of a phosphosilicate mixed network-former glass in which the phosphate groups selectively attract the Na+ modifier ions. Titanium takes a sub-octahedral coordination environment with a mean Ti-O coordination number of 5.17(4) for x = 0.8 and 4.86(4) for x = 1.0. A mismatch between the P-O and Si-O bond lengths of 8% is likely to inhibit the incorporation of silicon into the phosphorus sites of the NASICON crystal structure. (AU)

• 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