Glass

Glass is an inorganic, non-crystalline solid produced by cooling a melt without permitting crystallisation. Its structure is often described as a continuous random network of network-forming units—such as SiO₄ tetrahedra, B₂O₃ triangles or PO₄ groups—interlinked by bridging oxygen atoms. Incorporation of network modifiers (alkali and alkaline-earth cations) disrupts this network to adjust properties such as viscosity, thermal expansion and chemical durability. Soda–lime–silica glass remains the dominant commercial composition, prized for its low cost and optical transparency, while borosilicate and alumino-silicate formulations offer enhanced thermal and chemical stability. Beyond architectural and container uses, glass underpins optical fibres, laser hosts, display technologies, radiation-shielding windows and bioactive devices. Its lack of long-range order gives rise to a glass transition range rather than a sharp melting point, enabling precision forming methods such as float processing and precision moulding. Functionalisation through rare-earth doping, metallic nanoparticles or embedded quantum dots has created active photonic components, high-performance waveguides and sensors. Contemporary advances in spectroscopic, microscopic and in-situ laser techniques continue to refine our understanding of structure–property relationships, guiding the design of sustainable, high-resilience glasses for telecommunications, renewable energy, cultural heritage conservation and intelligent building façades.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Research from all publishers

Recent work on tellurite glass has demonstrated an in-situ striking approach that combines controlled crucible corrosion and powder-reheating to grow gold nanoparticles with precise size and concentration. The resulting plasmonic resonances, tunable across the visible and near-infrared, align closely with Mie-theory models and open pathways to photonic modulation and sensing within a glass host. A comprehensive 2023 review of photonic glasses has synthesised progress in scattering-based colour generation, light-localisation effects and multifunctional coatings, emphasising angle-resolved and time-resolved spectroscopies as vital tools for probing disorder-induced band-edge phenomena in recyclable, low-cost matrices. In the realm of photo-thermo-refractive glass, zero-order chirp-controlled Bessel beams from ultrafast lasers have been used to inscribe sub-micrometre fluoride nanocrystals directly within the glass. Subsequent heat treatment tunes refractive-index changes by several hundred ppm, enabling high-resolution Bragg gratings and waveguides without additional polishing steps, thereby advancing on-chip integrated photonic elements.

Glass publication trend

The graph below shows the total number of articles in glass across all publications each year (not limited to Nature Index journals).

Technical terms

Continuous random network: A depiction of the disordered connectivity of polyhedral units (e.g. SiO₄) in a glass, lacking periodicity beyond nearest neighbours.

Network former: An ion (e.g. Si⁴⁺, B³⁺) that builds the backbone of a glass via strong, directional bonds to bridging oxygens.

Network modifier: A cation (e.g. Na⁺, Ca²⁺) that interrupts the glass network by creating non-bridging oxygens and thereby alters viscosity and thermal expansion.

Glass transition temperature: The midpoint of the temperature range over which a supercooled liquid gradually becomes a rigid glass, marked by a change in heat capacity or volume expansion.

Localised surface plasmon resonance (LSPR): A collective oscillation of conduction electrons confined to metallic nanoparticles, producing distinct absorption and scattering peaks.

Photo-thermo-refractive glass: A photosensitive multicomponent glass that, upon UV or ultrafast-laser exposure followed by thermal annealing, nucleates nanocrystals to create precise refractive-index patterns.

References

1. Controlled formation of gold nanoparticles with tunable plasmonic properties in tellurite glass. Light: Science & Applications (2023).
2. The past, present and future of photonic glasses: A review in homage to the United Nations International Year of glass 2022. Progress in Materials Science (2023).
3. Nano-Crystal and Microstructure Formation in Fluoride Photo-Thermo-Refractive Glass Using Chirp-Controlled Ultrafast Laser Bessel Beams. Nanomaterials (2021).