High temperature X-ray diffraction study of LiGaO2

In recent years LiGaO2 has been gaining attention as a substrate material f or the growth of GaN. Since film deposition is generally carried out at hig h temperatures the behavior of the substrate at processing temperatures sho uld be known. The lattice constants of polycrystalline LiGaO2 were measured from room temperature to 1423 K and the linear thermal expansion coefficie nts in the temperature range between 293 and 1423k were determined to be al pha (a) = 10.1 +/- 0.2 x 10(-6) K-1, alpha (b) = 21.1 +/- 0.3 x 10(-6) K-1, and alpha (c) = 13.6 +/- 0.2 x 10(-6) K-1. High temperature X-ray powder d iffraction data show that at above 1173 K the Ga rich phases, LiGa5O8 and G a2O3, start to form indicating volatilization of the Li from the structure. (C) 2001 Elsevier Science B.V. All rights reserved.