Earth and Planetary Science
EPS Geophysics

DEC 2012 - High pressure research unravels mysteries of nanomaterials

Over the last years Rudy Wenk’s group in the department has developed methods to investigate deformation of materials at ultrahigh pressures with diamond anvil cells. It was observed that brittle minerals such as olivine, perovskite and postperovskite become ductile above 20 GPa. This approach has been applied to study deformation mechanisms of rocks at deep Earth conditions and was applied to explain seismic anisotropy. A recent collaboration of Rudy and graduate student Jane Kanitpanyacharoen with scientists at the high pressure beamline 12.2.2. of the Advanced Light Source applied the technique to nanocrystalline metals which were generally thought not to be subject to dislocation glide. Yet at 37 GPa synchrotron X-ray diffraction images reveal that preferred orientation developed in nanocrystalline nickel, suggesting that also here pressure promotes dislocation activity. It highlights the university as a forum for interdisciplinary interaction, where methods developed by earth scientists to investigate the deep earth are used by engineers to shed light on puzzles of nanomaterials, one of the big issue in materials science. The novel results are reported in the recent issue of Science.