A clearer understanding of the role of zinc in glass structure brings the optimization of electronic displays a step forward*

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Glasses are traditionally based on silicon (Si) but can also be formed by other elements, such as boron (B) and molybdenum (Mo). This is the case of boromolybdate glasses, which can be doped with other elements to change their properties. These glasses also contain zinc (Zn) and, in comparison to traditional silicon based glasses, they have high electrical conductivity and a lower melting point. This makes them interesting for applications in consumer electronics such as TVs and smartphone touch displays. Although boromolybdate glasses are already widely used, some questions on their atomic structure are still open. In particular, the exact role of zinc within the glass was not yet completely clear. The basic theory claims that the main structure is formed by boron and molybdenum. Zinc plays the role of a modifier, which only influences the structure without being part of it.

TEM images of 30MoO3–50ZnO–20B2O3 glassy sample

Margit Fabian, from the Hungarian Academy of Sciences, recently found evidence that contradicts this theory. In her study, supported by CERIC-ERIC, she used Neutron Diffraction, High Resolution Electron Microscopy and Solid- State Nuclear Magnetic Resonance together with computational simulation methods, to reveal the structure of several zinc-boromolybdate glasses with different compositions. The study not only produced precise structural data but also revealed that zinc plays an active role in forming the structure and is also fully incorporated. This new information is an important step towards a deeper understanding of this interesting class of materials and helps further to optimize the glasses for potential application.

Original article

M. Fabian, E. Svab, K. Krezhovc, Network structure with mixed bond-angle linkages in MoO3–ZnO–B2O3 glasses: Neutron diffraction and re- verse Monte Carlo modelling, Journal of Non-Crystalline Solids, Vol. 433, 2016, 6–13 (published online Nov. 2015)