Crystallization, Phase Stability, Microstructure, and Chemical Bonding in Ga(2)O(3) Nanofibers Made by Electrospinning

[Image: see text] We report on the crystal structure, phase stability, surface morphology, microstructure, chemical bonding, and electronic properties of gallium oxide (Ga(2)O(3)) nanofibers made by a simple and economically viable electrospinning process. The effect of processing parameters on the properties of Ga(2)O(3) nanofibers were evaluated by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Thermal treatments in the range of 700–900 °C induce crystallization of amorphous fibers and lead to phase stabilization of α-GaOOH, β-Ga(2)O(3), or mixtures of these phases. The electron diffraction analyses coupled with XPS indicate that the transformation sequence progresses by forming amorphous fibers, which then transform to crystalline fibers with a mixture of α-GaOOH and β-Ga(2)O(3) at intermediate temperatures and fully transforms to the β-Ga(2)O(3) phase at higher temperatures (800–900 °C). Raman spectroscopic analyses corroborate the structural evolution and confirm the high chemical quality of the β-Ga(2)O(3) nanofibers. The surface analysis by XPS studies indicates that the hydroxyl groups are present for the as-synthesized samples, while thermal treatment at higher temperatures fully removes those hydroxyl groups, resulting in the formation of β-Ga(2)O(3) nanofibers.