Experimental determination of the pyrolysis temperatures of an organometallic complex to obtain AlxGa1-xN powders

Abstract

AlxGa1-xN powders were obtained by pyrolysis route of the (CH6N4O)3 Al-Ga(NO3)3 organometallic complex, followed by an annealing in anhydrous ammonia flow at 1000 °C during two hours. Pyrolysis temperatures were experimentally determined in a range from 200 to 285 °C, which was systematically checked by thermal gravimetric analysis and differential scanning calorimetry, and whose results agree with the experimental pyrolysis temperatures. X-ray diffraction patterns for the AlxGa1-xN powders showed a slight shift towards greater angles, when the aluminum concentration increases. Scanning electron microscopy micrographs, showed the presence of agglomerates, which generate the formation of not well-defined plates with rough texture into the AlxGa1-xN powders. However, high-resolution transmission electron microscopy micrographs showed well-defined nanocrystals with a crystal size of 9 nm. Energy dispersive spectroscopy showed that there is no presence of carbon atoms in the AlxGa1-xN powders. Cathodoluminescence spectra for the AlxGa1-xN powders showed emissions in a range from 359 nm (3.45 eV) to 205 nm (6.04eV) (UV region).