Can we make a new phase of carbon?

Nearly all materials undergo a series of transformations to new crystal structures under high loads. Many materials, such as silicon and carbon, can form new metastable crystal structures that are stable after the application of extreme pressures. Examples of such metastable structures include a new form of silicon that has improved solar applications and a new form of diamond that is predicted to be 'harder-than-diamond'.

The formation pathways of such new phases is of obvious technological and scientific interest and whilst there has been much work on the effect of hydrostatic high pressure environments, the effect of shear is relatively unknown. Our recent work has shown that shear may actually be key in lowering the barrier to such phases. This project aims to investigate this possibility by the use of both novel diamond anvil cell designs and novel precursor material.

A variety of processing and characterisation methods will be employed including X-ray synchrotron studies via powder diffraction, diamond anvil cells, nanoindentation, Raman microspectroscopy and a number of ex-situ microscopy techniques.