By exploiting variable-temperature tapping mode (TM) atomic force microscopy in O-2 and N-2, the thermally activated degradation pathways of the tris(8-hydroxyquinoline) aluminum (Alq(3)) thin film on indium-tin-oxide coated glass substrate have been studied as functions of temperature and time. Results suggest that the Alq(3) thin film was thermally and chemically stable up to 125 degrees C in O-2 and N-2 atmospheres. No thermal oxidation of the thin film was detected by Fourier transform infrared spectroscopy. Apparent glass transition of the Alq(3) thin film took place at 130 degrees C, well below the generally reported glass transition temperature of 170 degrees C or so. Crystallization of the Alq(3) thin film occurred at 185 degrees C. (c) 2005 Published by Elsevier B.V.