Raman spectroscopy of the transition of α-gallium oxyhydroxide to β-gallium oxide nanorods

The thermo-Raman spectra of synthesised a-gallium oxyhydroxide nanorod prove that the transition of a-gallium oxyhydroxide to beta-gallium oxide nanorods occurs above 350 degrees C but below 400 degrees C. Scanning electron microscopy proves that the morphology of the a-gallium oxyhydroxide nanorods is retained upon calcination to P-gallium oxide. X-ray diffraction patterns show that the nanorods are a-gallium oxyhydroxide converting upon calcination to beta-gallium oxide. Intense Raman bands are observed at 190, 262, 275, 430, 520, 605, and 695 cm(-1), which undergo a red shift of similar to 5 cm(-1) upon heating to 350 degrees C. Upon thermal treatment above 350 degrees C, the Raman spectrum shows a significantly different pattern. Raman bands are observed at 155, 212, 280, 430, 570, and 685 cm(-1). The thermo-Raman spectra are in harmony with the TG and DTG patterns, which show that the reaction of a-gallium oxyhydroxide to beta-gallium oxide occurs at 365 degrees C. Copyright (C) 2008 John Wiley & Sons, Ltd.