siliconoxide

Silicon oxide is the term used for chemical compounds composed of silicon and oxygen. The most common member is silicon dioxide (SiO2), which occurs widely in nature and industry. SiO2 exists in crystalline forms—quartz, cristobalite, and tridymite—and in amorphous forms such as fused silica, glassy silica, and hydrated silicas like opal and silica gel. Silicon monoxide (SiO) is a less stable oxide that can form at very high temperatures but readily disproportionates to Si and SiO2.

In nature, SiO2 minerals dominate a large portion of the Earth's crust. Industrially, silica is extracted from sand and processed into glass, cement, ceramics, fillers, and adsorbents. A key process in electronics is the growth of silicon dioxide layers by thermal oxidation of silicon, which yields insulating gate oxides and protective coatings for silicon-based devices.

Properties: Silicon oxide compounds are typically hard and thermally stable. SiO2 is a poor conductor of electricity and is chemically inert to many acids, though it dissolves in hydrofluoric acid. The structural form influences optical properties: crystalline quartz is birefringent, while fused silica is highly transparent in the visible and near-infrared.

Applications: Glass making, cement and ceramics, catalysts supports, desiccants (silica gel), and fillers in polymers and papers. In advanced technology, SiO2 serves as an essential dielectric in semiconductor devices and as an optical fiber material.

Safety: crystalline silica dust poses serious health risks, including silicosis, and is regulated in occupational settings.