A compact route for efficient production of high-purity β-Ga₂O₃ powder

The present study has proposed a compact process for the production of high-purity β-Ga₂O₃ powder by simply using gallium metal and water as the raw materials. The process basically consists of two essential steps including hydrothermal synthesis of GaOOH and calcination of GaOOH for the production of the target product of β-Ga₂O₃. Thermodynamic evaluation and systematic experiments were conducted for process parameter optimization. X-ray diffractometer (XRD), scanning electron microscopy (SEM), thermogravimetry–differential scanning calorimetry (TG-DSC) and X-ray photoelectron spectroscopy (XPS) were utilized to clarify the reaction mechanisms of the hydrothermal synthesis and transformation of GaOOH to β-Ga₂O₃ by calcination. Chemical analysis of the final product of β-Ga₂O₃ obtained under the optimal conditions was carried out with inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that the contents of the representative impurities such as Ni, Cu, In, Mn, Co, Zn and Cr are obviously lower than the requirement of 5N β-Ga₂O₃ standard, exhibiting excellent application prospect of the proposed process to produce high-purity β-Ga₂O₃.