Features of Synthesis of InGaMgO4 from Nitrate-Organic Precursors and Study of Its Physical Properties

This work reports on the possibility of producing oxide InGaMgO4 by two-stage heat treatment of glycine-, starch- and PVA-nitrate precursors. The products formed as a result of their heating at low temperatures (≈ 90°С) were studied by powder X-ray diffraction. It was found that the powder formed from the glycine-nitrate precursor contains nanocrystalline In2O3, and drying of the polymer-nitrate compositions leads to the production of a thermally stable X-ray amorphous product. Its annealing at temperatures above 800°C allows synthesizing powder InGaMgO4 free of impurity phases. High-temperature treatment of the powder formed from the glycine-nitrate precursor also leads to the production of InGaMgO4, but does not remove the In2O3 impurity. Using scanning electron microscopy, it was found that single-phase InGaMgO4 powders synthesized from polymer-nitrate precursors have a similar grain structure but differ in grain size distribution. Presumably, this difference is due to the structural features of starch and PVA macromolecules used for the preparation of precursors. Oxide InGaMgO4 was characterized using differential scanning calorimetry, Raman and diffuse reflectance spectroscopy. The value of its band gap energy Eg was determined using the Tauc method.