Thermal stability and electronic specific heat of GaN

Abstract The thermal stability of GaN single crystals obtained by Li-based flux was investigated by DTA–TG, XRD, Raman and infrared spectroscopy. The results evidence that pure GaN becomes unstable above 900 °C under N 2 of 0.1 MPa. The specific heat of GaN was determined at temperatures ranging from 1.9 K to 80 K. Its electronic specific heat coefficient is 0.47 mJ K −2  mol −1 and the Debye temperature is 278 K.