Synthesis of Yttrium Oxide Nanocrystal via Solvothermal Process

Abstract

Y₂O₃ nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y₂O₃ in order to obtain better materials performance. In present study, yttrium oxyhydroxide precursor was synthesized via a facile solvothermal process through the dissolution-recrystallization mechanism of Y₂O₃ raw powders in the ethylenediamine solvent, then nanosized yttrium oxide crystal was prepared from the precursor through post heat treatment process. The effects of solvothermal treatment temperature, holding time, solvent kinds and post heat treatment parameters on crystalline structure, grain shape and size of nanocrystal were investigated by XRD, TEM and TGA-DTA measurements. TEM images reveal that the morphology of product after post heat treatment at 460 °C for 12 h is rice-like nanocrystal. XRD shows that this product is pure cubic Y₂O₃ cphase. Present study reveals that high purity Y₂O₃ with rice-like morphology can be easily prepared with average size around 30 nm under suitable post heat treatment parameters. In addition the effects of solvents such as water and ethanol etc. on the crystal structure and morphology were also investigated. It is suggested that dissolution-recrystallization process may be the main mechanism for the formation of nano-sized YOOH precursors under solvothermal reaction condition, and the ethylenediamine solvent is likely to play an important role in controlling the transformation process of yttria precursors to the Y₂O₃ nanocrystal.