Melt-quenched oxide glasses with ultrahigh Young's modulus and small thermal expansion coefficient

The well-known Makishima-Mackenzie relationship, consisting of two terms of the dense packing structure and dissociation energy regarding bonding in constituent oxides, enables fabricating oxide glasses with ultrahigh Young's modulus (similar to 140 GPa) and a small coefficient of thermal expansion (CTE) (similar to 4 ppm/K). The effects of increasing MgO and Ta2O5 contents in an MgO-Ta2O5-Al2O3-SiO2-B2O3 glass system using a conventional melt-quenching method are revealed. The essential oxides of Al2O3 and Ta2O5 are primarily suitable for dense packing structures dominated by a large coordination number of oxygens. The substitution of CaO by MgO results in high dissociation energy when the glass composition falls in the peraluminous regime (Al2O3/[MgO + CaO] > 1). A small CTE is realized by increasing the molar ratio of Al2O3/MgO. According to magic-angle spinning-nuclear magnetic resonance spectra, mechanically and thermally functional oxide glasses depend on their structures. These findings facilitate the development of glass substrate applications without thermal dilatation.

Automated summary

The Makishima-Mackenzie relationship, which involves dense packing structures and dissociation energy in oxides, allows the fabrication of oxide glasses with high Young's modulus and a small coefficient of thermal expansion. Increasing MgO and Ta2O5 contents in a glass system leads to these desired properties. The oxides Al2O3 and Ta2O5 play a crucial role in dense packing structures.