Dominating migration barrier for intrinsic defects in gallium oxide: Dose-rate effect measurements

Ion bombardment provides an opportunity to study basic properties of intrinsic defects in materials since the radiation-induced disorder accumulation depends on the balance between defect generation and migration rates. In particular, variation of such parameters as irradiation temperature and ion flux, known in the literature as dose-rate effect, interconnects the macroscopically measured lattice disorder with the migration barrier of the dominating defects. In this work, we measured the dose-rate effect in monoclinic gallium oxide (beta -Ga2O3) and extracted its activation energy of 0.8 +/- 0.1eV in the range of 25-250 degrees C. Taking into account that the measurements were performed in the Ga-sublattice and considering 0.8 +/- 0.1eV in the context of theoretical data, we interpreted it as the migration barrier for Ga vacancies in beta -Ga2O3, limiting the process. Additionally, we observed and took into account an interesting form of the lattice relaxation due to radiation-induced disorder buildup, interpreted in terms of the compressive strain accumulation, potentially trigging phase transitions in Ga2O3 lattice.

Automated summary

Ion bombardment provides an opportunity to study the basic properties of intrinsic defects in materials, depending on the balance between defect generation and migration rates. This study measured the dose-rate effect in β-Ga2O3 and extracted an activation energy of 0.8 ± 0.1eV, while also observing lattice relaxation due to radiation-induced disorder buildup.