Silicon monoxide (SiO) is a noncrystalline material valued for its distinctive combination of optical, electrical, and structural properties. As an amorphous compound that differs fundamentally from both silicon and silica, SiO has become an important material in thin-film technologies, optics, microelectronics, and energy storage systems. Its unique bonding structure and tunable deposition properties make it one of the most versatile oxide materials in modern materials science.
Material Overview
SiO is typically produced by heating silicon and silica in a vacuum, yielding an amorphous material composed of silicon atoms bonded in silicon–oxygen tetrahedra rather than forming a simple mixture of silicon and SiO2 (Hass, 1950; Batsanov, 2016). This structure results in distinct electronic and optical behavior compared to crystalline silicon or quartz. The material exhibits a stable refractive index and extinction coefficient when synthesized in oxygen-free conditions, making it ideal for optical and dielectric applications (Philipp, 1997).
Physically, SiO has a density of approximately 2.13 g/cm³ and a low thermal expansion coefficient comparable to that of elemental silicon, reducing thermal stress during temperature cycling (Chand et al., 1994). Chemically, it is reactive with acidic fluoride solutions containing metals such as silver, copper, or mercury, a property utilized for calorimetric studies of formation enthalpy (Wartenberg, 1949). Its amorphous nature also confers excellent film-forming capabilities, allowing for uniform coatings with good adhesion and controlled intrinsic stress depending on deposition conditions.
Applications and Advantages
Microelectronics and thin-film technologies. SiO serves as a key dielectric material in semiconductor fabrication due to its combination of optical transparency, electrical insulation, and chemical stability. It is commonly used as an interlayer dielectric, protective coating, and antireflective layer in integrated circuits and optical sensors (Chand et al., 1994; McMillan & Misra, 1970). Its ability to form adherent and uniform thin films via vacuum deposition makes it suitable for precise microelectronic and optoelectronic applications.
Optical and protective coatings. Owing to its stable refractive index, SiO is employed in high-quality mirror coatings, antireflective layers, and protective films for optical components (Hass, 1950). It is also used in the preparation of thin films for electron microscopy and diffraction studies, where its amorphous nature minimizes interference effects and enhances image clarity.
Energy storage and emerging applications. Recently, amorphous SiO has attracted attention as a promising anode material for lithium-ion batteries, offering high theoretical capacity and improved cycle performance compared to traditional silicon-based anodes (Weibo, 2018). The ability to tune intrinsic stress in SiO thin films by adjusting oxygen partial pressure further broadens its applicability in flexible electronics and stress-sensitive devices (Chand et al., 1994).
Goodfellow Availability
Goodfellow provides high-purity silicon monoxide (SiO) for research, prototyping, and advanced manufacturing. Available in powders, our SiO materials are produced to exacting specifications to ensure consistent optical, electrical, and mechanical performance. Custom dimensions and compositions can be supplied to meet specific project or experimental requirements.
Explore Silicon Monoxide (SiO) and other advanced materials in Goodfellow’s online catalogue: Goodfellow product finder.
References
- Hass, G. (1950). Preparation, Structure, and Applications of Thin Films of Silicon Monoxide and Titanium Dioxide. Journal of the American Ceramic Society. https://doi.org/10.1111/J.1151-2916.1950.TB14151.X
- Batsanov, S. S. (2016). Optical properties and structure of silicon monooxide. Russian Journal of Physical Chemistry A. https://doi.org/10.1134/S0036024416010040
- Chand, N., Kola, R. R., Osenbach, J. W., & Tsang, W.-T. (1994). Tunability of Intrinsic Stress in Siox Dielectric Films Formed by Molecular Beam Deposition. MRS Proceedings. https://doi.org/10.1557/PROC-356-195
- Weibo, M. (2018). Highly amorphous silicon monoxide material and preparation method and application thereof.