High-pressure and high-temperature behaviour of gallium oxide

摘要

High-temperature and high- pressure behaviours of beta-Ga2O3 powder are studied by energy- dispersive x- ray diffraction in a diamond anvil cell (DAC). It is found that the phase transition from the monoclinic beta-Ga2O3 to the trigonal alpha-Ga2O3 occurs at around 19.2GPa under cold compression. By heating the powder to 2000K at 30GPa, we confirm that alpha-Ga2O3 is the most stable structure at the high pressure. Furthermore, the structural transition from beta-Ga2O3 to alpha-Ga2O3 is irreversible. After laser heating, the recrystallized Ga2O3 has a preferable (012) orientation. This interesting behaviour is also discussed.