Glass - Back to the Future!

Presenting Author:
Akira Takada

article posted 30 March 2016

Akira TakadaAfter graduating from Tokyo University at which I studied applied mathematics, I joined Asahi Glass Company. I have been performing a variety of computer simulations of macroscopic and microscopic phenomena on glass. My recent major concern is to construct a bridge between microscopic (glass structure) and microscopic phenomena (glass properties) on glass. I am joining the activities of TC-3 (Glass Structure) and TC-27 (Atomistic modelling and Simulation) under ICG. In addition, I have a research project at University College London as a visiting professor.

I have recently finished my presidency at the Japan Society of Industrial and Applied Mathematics (JSAM; a number of member is about 1,700). I am a member of Science Council of Japan.

Geometrical modelling of silica crystals and glasses

Akira Takada
Asahi Glass Company, 1150 Hazawa-cho, Kanagawa-ku, Yokohama 221-8755, Japan

Since Bernal proposed liquid structures could be understood by the concept of random close-packed model, many theoretical studies have been carried out for modelling monatomic liquids and amorphous metals with the increase of the power of computers.
However, oxide glasses like silicate glass are comprised of species with different atomic radius and they do not have close-packed structure. In this study, the author investigated the structural features of silica polymorphs and glasses in terms of Voronoi tessellation. It is found that the difference in coordination numbers, local volume and geometrical symmetry between silica polymorphs and glasses can be distinguished in terms of Voronoi tessellation.

Fig. Local geometry found in silica crystals and glass.