Abstract
In this paper, the self-consistent PMMCS force fields (FFs) [Pedone et al., J. Phys. Chem. B 110, 11780 (2006)] widely used for the simulation of a large variety of silicates, aluminosilicate and phosphate crystals, and multicomponent oxide glasses have been revised and improved by the inclusion of two types of three-body interactions acting between T-O-T bridges ($T=\mathrm{Si}$ and P) and network former-network former repulsive interactions. The FFs named Bertani--Menziani--Pedone (BMP)-harm and BMP-shrm better reproduce the T-O-T bond angle distributions (BADs) and network former-oxygen distances. Consequently, the prediction of ${Q}^{n}$ distributions (Q stands for quaternary species, and $n$ is the number of bridging oxygens around it), neutron total distribution functions, solid-state nuclear magnetic resonance spectra of spin active nuclei ($^{29}\mathrm{Si}$, $^{17}\mathrm{O}$, $^{31}\mathrm{P}$, $^{27}\mathrm{Al}$), and the density have also been hugely improved with respect to the previous version of our FF. These results also highlight the strong correlation between the T-O-T BADs and the other short and intermediate structural properties in oxide glasses, which have been largely neglected in the past. In addition to the improvement of the structure, the FF has been revealed to reproduce well the ionic conductivity in mixed alkali aluminosilicate glasses and the elastic properties. The systematic comparison with other interatomic potential models, including the polarizable core-shell model, carried out in this paper showed that our potential model is more balanced and effective for simulating a vast family of crystalline and amorphous oxide-based systems.
Highlights
Multicomponent oxide glasses play a key role in addressing major global challenges in energy, medicine, and advanced communications systems [1,2] and are among the more used materials in the related industries.Being disordered materials, glasses do not have to fulfill stoichiometric restraints as crystals do, and their chemical composition is largely tunable, leading to a vast number of structures with uniquely refined combinations of properties [3]
Five interatomic potential models were examined: the pairwise rigid ionic model (RIM) proposed by Pedone et al [7,12], and Sundararaman et al [13], named PMMCS and SHIK potentials hereafter, two modified PMMCS potentials with the inclusion of two different kinds T-O-T three-body interactions developed in this paper (BMP-harm and BMP-shrm), and the core-shell model (CSM) with Si-O, Al-O, P-O, Na-O, K-O, and O-O parameters taken from Refs. [15,41,42]
Glass structural models containing about 1500 atoms were generated through the melt and quench approach by Molecular dynamics (MD) simulations except for the binary alkali-silicate glass models used to compute the Young modulus with the dynamic method for which boxes containing about 10 000 atoms were used
Summary
Multicomponent oxide glasses play a key role in addressing major global challenges in energy, medicine, and advanced communications systems [1,2] and are among the more used materials in the related industries. The development of glass compositions with tailored properties is hampered by the lack of a complete understanding of the structure of multicomponent oxide glasses This is understood as a continuous random network of coordination polyhedra made of the network-forming cations (T = Si, P, B, Ge) and oxygen. When Al2O3 is introduced into a modified silicate glass composition, Al cations predominantly form negatively charged (AlO4)1− units that are charge compensated by the modifying cations, and the concentration of NBO is reduced . We showed that the structural models of silicate, aluminosilicate, and borosilicate glasses generated using the CSM provide computed nuclear magnetic resonance (NMR) spectra in better agreement with experiments because this model better reproduces the T-O-T (T = Si, P, Al, B) bond angle distributions (BADs) than the RIM [38,39].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
