On the grain growth of CeO2 nanocrystals in AC/DC electrical fields

Abstract

Processing of materials using electrical field presents an important research and engineering field. It allows to process materials at less demanding conditions, synthesize new phases and compositions. Herein, nanocrystals of CeO2 were synthetized and grown in-situ under AC and DC electrical fields. Main crystallographic properties like crystallite size, morphology texture and grain boundaries were significantly influenced by the electrical field up to 600 °C. Above this temperature, the thermally driven grain growth hindered the electrical field effect and led to a common behavior, isotropic particle shape and surface properties. This can be linked to the electrical and thermal force competition for the grain boundary development. To our knowledge such comprehensive description of the field effect on the growth of nanocrystals and its limitations has never been reported and can open a new door for processing of nanocrystalline materials.