Modeling phase separation mechanisms in oxy‐fluoride glass‐ceramics containing SrF2:Ln3+ and ZnAl2O4:Cr3+ nanocrystals

Abstract

AbstractIt is imperative to develop a comprehensive understanding of phase separation mechanisms in multi‐phase oxy‐fluoride glass ceramics (GCs) to customize their structural and optical characteristics for particular applications in photonics. The manuscript utilizes molecular dynamics (MD) simulations to examine the phase separation mechanisms in SiO2–Al2O3–SrF2–ZnF2–LnF3‐CrF3 (where Ln represents the lanthanide elements) GCs during the simultaneous precipitation of SrF2: Ln3+ and ZnAl2O4: Cr3+ nanocrystals. Insights into the atomic‐level interactions that regulate the separation and formation of distinct phases rich in fluoride and oxide are obtained through MD simulations. The results reveal that Sr2+ and Ln3+ ions partition preferentially into the fluoride phase, whereas Zn2+ and Cr3+ associate with the oxide aluminosilicate network. Remarkably, the separated fluoride and oxide phases bear structural similarities with the existing experimental outcomes. The introduction of SrF2 facilitates phase separation in oxy‐fluoride glass system by causing the formation of SrF2: Ln3+ nanocrystals in regions abundant in fluoride, while the substitution of ZnF2 for SrF2 results in the formation of ZnAl2O4: Cr3+ nanocrystals originating from the separated oxide phase. Therefore, the reported simulations offer molecular‐level insights into the mechanisms underlying phase separation and the functions of various glass components, thereby facilitating the development of customized oxy‐fluoride GCs with tailored properties.