Lawrence Berkeley National Laboratory

In this paper, we introduced a method to measure grain rotation of nanomaterials under external stress using a high pressure diamond anvil cell and the Laue microdiffraction technique at a synchrotron facility. We used tungsten carbide marker crystals to investigate grain rotation activities of 3 and 500 nm nickel media. Our results show that the grain rotation of 3 and 500 nm nickel nanocrystals increase with pressure and finally rotation of 500 nm nickel tends to stop at a lower pressure/stress level than 3 nm nickel. 3 nm nickel nanocrystals show a higher rotation magnitude than 500 nm nickel nanocrystals. Our measurements show an effective method to study the grain rotation of nanomaterials especially in ultrafine nanocrystals.