Structure–Property Correlation in Ba/Sr–Ca–Mg–Zn–Si–Al–O\nGlass: Elucidation by Experimental and Molecular Dynamics Simulation\nStudy

Broad\nband transmitting glasses from visible to mid-infrared with\ngood mechanical strength, chemical durability, glass-forming ability,\nand thermal stability are preferred for optics and laser technology\napplications. Generally, low phonon energy glasses possess an extended\ntransmission cutoff toward mid-infrared, but at the same time, retention\nof other desired properties is challenging for the researchers. In\nthis work, we have shown that mixed alkaline earth (Ba/Sr) would have\nthe potential to improve overall glass properties while retaining\nits low phonon energy when CaO is partially substituted by BaO/SrO\nin calcium magnesium zinc silica–aluminate (CMZSA) glass. Quantitative\nstructure analysis of its role in glass properties has been carried\nout using molecular dynamics (MD) simulation and experimental techniques.\nThis study reveals that Al and Si mainly attained fourfold coordination,\nwhile Zn and Mg majorly existed in Al–O–Zn/Mg triclusters.\nThe Ba<sup>2+</sup> ions play almost equal roles as charge compensators\nand network modifiers, while Sr<sup>2+</sup> ions play a larger role\nin charge compensation. As a result, the SrO-added glass leads to\nthe highest bridging oxygens as compared to others and corroborates\nwith improved optical, thermal, and mechanical properties. Hence,\nthe SrO-added glass shows the most stable network connection and improved\noverall glass properties.