【Substrate Papers】High-yield synthesis of β-Ga₂O₃ via controlled hydrolytic precipitation from a gallium nitrate system

      Researchers from the Northeastern University have published a dissertation titled "High-yield synthesis of β-Ga₂O₃ via controlled hydrolytic precipitation from a gallium nitrate system" in Ceramics International.

Abstract

      The hydrolytic precipitation of gallium from a nitrate system was systematically investigated to elucidate the formation mechanism of gallium oxide (Ga₂O₃) and optimize the synthesis process for high yield. An orthogonal experimental design combined with single-factor optimization was employed to decouple the effects of pH, reaction temperature, and reaction time. The results demonstrated that solution pH is the critical thermodynamic parameter governing gallium speciation, with a narrow optimal window (centered at pH 6.0) favoring the formation of neutral Ga(OH)₃. Deviation into highly acidic or alkaline regimes promoted the formation of soluble ionic species, significantly reducing yield. Furthermore, reaction temperature was found to primarily influence the kinetics of nucleation and crystal growth, while reaction time showed a negligible effect on the final yield once the precipitation equilibrium was reached. Under the determined optimal conditions (pH = 6.0, reaction temperature = 65 °C, and reaction time = 20 min), a gallium recovery yield exceeding 98.98 % was achieved. Subsequent calcination of the precursor at 900 °C yielded pure-phase monoclinic β-Ga₂O₃ with high crystallinity. This study provides process parameters and a scalable technical route for the efficient industrial production of high-quality gallium oxide materials.

DOI：

https://doi.org/10.1016/j.ceramint.2026.01.334