Calcium environment in silicate and aluminosilicate glasses Probed by $^{43}$Ca MQMAS NMR experiments and MD-GIPAW calculations

Elisa Gambuzzi (1) , Alfonso Pedone (2) , Maria Cristina Menziani (1) , Frédéric Angeli (3) , Pierre Florian (4) , Thibault Charpentier (5)

1 UNIMORE - Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia
2 Department of Chemical and Geological Sciences [Modena]
3 SECM - Service d'Etudes du Comportement des Matériaux de Conditionnement
4 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation
5 NIMBE UMR 3685 - Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M)

$^{43}$Ca MQMAS NMR spectra of three silica-based glasses in which Ca$^{2+}$ ions play different structural roles have been collected and processed in order to extract the underlying NMR parameter distributions. The NMR parameters have been interpreted with the help of molecular dynamics simulations and DFT-GIPAW calculations. This synergetic experimental-computational approach has allowed us to investigate the Ca environment, to estimate Ca coordination numbers from MD-derived models, and to push further the discussion about $^{43}$Ca NMR sensitivity to the first and second coordination spheres: $^{43}$Ca $\delta_{iso}$ and Ca-O distance can be successfully correlated as a function of Ca coordination number.

Mots clés: $^{43}$Ca MQMAS NMR spectroscopy; Oxide glasses; Molecular Dynamics simulations; GIPAW

Domaines: Chimie-Physique [physics.chem-ph]

Elisa Gambuzzi, Alfonso Pedone, Maria Cristina Menziani, Frédéric Angeli, Pierre Florian, et al.. Calcium environment in silicate and aluminosilicate glasses Probed by $^{43}$Ca MQMAS NMR experiments and MD-GIPAW calculations. Solid State Nuclear Magnetic Resonance, 2015, 68-69, pp.31-36. ⟨10.1016/j.ssnmr.2015.04.003⟩. ⟨hal-01157457⟩