Department of Materials Science & Metallurgy

Professor of Materials Science

MA University of Cambridge
PhD University of Cambridge

+44 (0)1223 334308
alg13@cam.ac.uk
www.msm.cam.ac.uk/mkg/

Microstructural Kinetics

My interest is in how materials change their structures. Understanding the mechanisms of these transformations is relevant not only for assessing the stability of materials, but also for developing new microstructures, properties and functionalities.

Metallic glasses

One route to new structures is to move further from equilibrium, and metallic glasses are a good example. Now that metallic glasses are available with minimum sections of the order of 1 cm, there is much interest in their mechanical properties, notably their exceptionally high strength, elastic strain and elastic energy-storage capacity. We focus on the mechanisms of plastic flow under ambient conditions.

Phase nucleation

Nucleation is the first step in phase transformations. Deliberate promotion of nucleation, whether in industrial processing such as the grain refinement of aluminium, or the control of ice formation by living systems, remains imperfectly understood, but our recent work shows that the nucleation kinetics can be quantitatively predicted.

Chalcogenides for data storage

Chalcogenide alloys can be reversibly switched between glassy and crystalline states. This switching can be exploited in data storage, whether in DVDs or RAM. It is also of interest in cognitive computing. Our research, challenging because of the ultra-short switching times, focuses on maximizing data-storage density.

Electromigration

The migration of atoms when an electrical current flows in a material gives reliability problems in integrated circuits, but can also be used to develop novel structures. The competition between the effects of current and those of composition gradient (shown in the figure) is highlighted and exploited in our work.