Abstract The dielectric properties and thermal behaviour of a precursor can provide theoretical support for microwave synthesis related materials and applications. Herein, the properties of both gallium oxide (β-Ga2O3) and gallium oxide hydroxide (α-GaOOH) were studied in detail from 22 °C to 800 °C. The results showed that the dielectric constant (er′) of β-Ga2O3 exhibited an increasing trend with increasing temperature, such a tendency was more obvious after 700 °C, while the dielectric loss (er″) for β-Ga2O3 was continuously reduced to a value of 0.061 (F/m) until 200 °C due to the removal of moisture in the initial stage. Next, er″ for β-Ga2O3 began to increase, reached a maximum value of 0.209 (F/m) at 700 °C, and finally decreased to 0.200 (F/m) at 800 °C. Meanwhile, the calculated loss tangent coefficient of α-GaOOH and β-Ga2O3 indicate that the microwave absorption capabilities of the two substances are approximately equal. Furthermore, the effect of size on dielectric parameters is investigated as the temperature increases. The evolution of morphology and structure was tracked during synthesis of β-Ga2O3 by microwave calcination of α-GaOOH, and results show that the single crystal β-Ga2O3 can be successfully synthesized by microwave calcination to 700 °C for 30 min. This work not only provides some data for the dielectric dispersion behaviour of α-GaOOH and β-Ga2O3, but also proves the feasibility of microwave heating α-GaOOH to prepare β-Ga2O3.

中文翻译：

---

GaOOH微波煅烧合成β-Ga2O3过程中的介电性能、结构和形貌

摘要 前驱体的介电特性和热行为可为微波合成相关材料和应用提供理论支持。在此，详细研究了氧化镓 (β-Ga2O3) 和氧化镓氢氧化物 (α-GaOOH) 在 22°C 至 800°C 下的性质。结果表明，β-Ga2O3 的介电常数（er'）随着温度的升高呈现增加趋势，这种趋势在 700°C 后更为明显，而 β-Ga2O3 的介电损耗（er”）不断降低至0.061 (F/m) 的值直到 200 °C 由于在初始阶段去除水分。接下来，β-Ga2O3的er″开始增加，在700℃达到最大值0.209(F/m)，最后在800℃降低到0.200(F/m)。同时，α-GaOOH 和 β-Ga2O3 的计算损耗角正切系数表明两种物质的微波吸收能力大致相等。此外，随着温度的升高，研究了尺寸对介电参数的影响。在α-GaOOH 的微波煅烧合成β-Ga2O3 过程中跟踪了形貌和结构的演变，结果表明单晶β-Ga2O3 可以通过微波煅烧至700°C 30 分钟成功合成。该工作不仅为α-GaOOH和β-Ga2O3的介电色散行为提供了一些数据，而且证明了微波加热α-GaOOH制备β-Ga2O3的可行性。随着温度的升高，研究了尺寸对介电参数的影响。在α-GaOOH 的微波煅烧合成β-Ga2O3 过程中跟踪了形貌和结构的演变，结果表明单晶β-Ga2O3 可以通过微波煅烧至700°C 30 分钟成功合成。该工作不仅为α-GaOOH和β-Ga2O3的介电色散行为提供了一些数据，而且证明了微波加热α-GaOOH制备β-Ga2O3的可行性。随着温度的升高，研究了尺寸对介电参数的影响。在α-GaOOH 的微波煅烧合成β-Ga2O3 过程中跟踪了形貌和结构的演变，结果表明单晶β-Ga2O3 可以通过微波煅烧至700°C 30 分钟成功合成。该工作不仅为α-GaOOH和β-Ga2O3的介电色散行为提供了一些数据，而且证明了微波加热α-GaOOH制备β-Ga2O3的可行性。