Glass - Back to the Future!

Presenting Author:
Robert J Newport

article posted 25 May 2015

Professor Robert J Newport Bob's research was focused on understanding the atomic-scale structure of novel amorphous (non-crystalline) materials of contemporary interest such as non-linear optical glasses and "sol gel" glasses which may be catalytically or biologically active. The structure of a given material is arguably the key factor in determining its macroscopic properties: the ethos of his work derives from his central interest in explaining why novel amorphous materials behave in the way they do: in other words to provide the research that will underpin a full understanding of their attributes. His firm belief is that complex materials or systems can rarely, if ever, be fully understood at the atomic/molecular or mesoscopic level if only a single experimental technique is used. He therefore sought to adopt, and to develop, a research methodology which embraces a wide range of traditionally disparate structural probes in an attempt to provide a more complete, and hence robust and widely applicable, picture. These include the use of a number of x-ray and neutron scattering techniques, together with computer simulation and modelling and many other complementary methods such as IR and Raman spectroscopy, ... . His team's work has been truly interdisciplinary, involving experimental and theoretical work in, and links with chemistry, engineering, materials science and bio/medical-engineering.

Probing crystallization of a fluoro-apatite - mullite system using neutron diffraction

J M Smith1,2, R A Martin3*, D T Bowron4, A C Hannon4, R J Newport1.

*Corresponding author:

Real-time small angle neutron scattering and wide angle neutron scattering studies were undertaken concurrently on a glass ionomer of nominal composition 4.5(SiO2)-3(Al2O3)-1.5(P2O5)-3(CaO)-2(CaF2). Neutron studies were conducted as a function of temperature to investigate the crystallisation process. No amorphous phase separation was observed at room temperature and the onset of crystallisation was found to occur at 650C, which is 90C lower than previously reported. The first crystalline phase observed corresponded to fluorapatite; it was only upon further heating was the mullite phase became present. The crystallite size at 650C was found to be ~ 115 Å and the result was consistent across all measurements.

1 School of Physical Science, University of Kent, Canterbury, CT2 7NH, UK
2 Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
3 School of Engineering & Applied Science and Aston Research Centre for Healthy Ageing, Aston University, Birmingham, B4 7ET, UK
4 ISIS Facility, Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX, UK