PhD position: Mapping a glassy “phase diagram”

Understanding the nature and structure of materials far-from-equilibrium is one of the remaining grand challenges in condensed matter physics [1]. Far-from-equilibrium phenomena can be seen in many diverse scientific disciplines and across many lengths scales including glasses, cellular systems, granular flows and earthquakes. Thus, advances in the underlying physics of out-of-equilibrium systems can have far-reaching implications across a large range of fundamental and applied areas. Glasses are a prototypical example of materials that are out-of-equilibrium. Yet, scientists have many unanswered questions about these materials. How can a material retain the disordered structure of a liquid, and yet be solid? Why do some materials form glasses more easily than others? What structure underlies the brittle fracture of glasses?

A key impediment to fresh understanding of the glassy state is an experimental technique to measure disordered structures. Current techniques in crystallography can only determine the structure of periodic objects. A series of new and measureable structural parameters for glasses has recently been proposed [2,3] and demonstrated by Monash University researchers using scanning micro-small-angle x-ray scattering [4] and colloidal glasses. In this experiment, it was shown for the first time, how local structures in the colloidal glass could be varied widely by varying the interaction between particles. Intriguingly, this local order in the glass could be linked to the local order in the underlying, lower density, crystalline phase diagram [4].

This project will involve complete mapping of the local order in glassy “phase diagrams” for one and two-component colloidal glasses with round and elliptical particles and a range of interaction-tuning additives. It will involve experiments at the Australian Synchrotron, the Monash Centre for Electron Microscopy and the Ramaciotti Centre for Cryo-EM and collaboration with A/Prof. Rico Tabor (School of Chemistry, Monash university). The project would suit a student with interests in experimental physical chemistry and soft matter, scattering methods and the development of new data analysis tools.

References

[1] National Academy of Sciences Report Condensed Matter and Materials Physics, 2010.

[2] A. C. Y. Liu, M. J. Neish, G. Stokol, G. A. Buckley, L. A. Smillie, M. D. de Jonge, R. T. Ott, M. J. Kramer, and L. Bourgeois, Phys. Rev. Lett. 110, 205505, (2013)

[3] A. C. Y. Liu, R. F. Tabor, L. Bourgeois, M. D. de Jonge, S. T. Mudie, and T. C. Petersen, Phys. Rev. Lett., 116, 205501 (2016)

[4] A. C. Y. Liu, R. F. Tabor, M. D. de Jonge, S. T. Mudie, and T. C. Petersen, Proc. Nat. Acad. Sci., 114, 10344–10349, (2017)