Under CopyrightSteffens, MichaelMichaelSteffensVianden, ReinerReinerViandenPasquevich, Alberto F.Alberto F.Pasquevich2022-03-1316.2.20172016https://publica.fraunhofer.de/handle/publica/39502510.24406/publica-fhg-395025Ga2O3 is a promising material for use in ""solar-blind"" UV-detectors which can be produced efficiently by oxidation of GaN. In this study we focus on the evolution of the oxide layer when GaN is heated in air. The experimental method applied is the perturbed angular correlation of g-rays emitted by radioactive nuclides, here ¹¹¹In and ¹8¹Hf, which are ion implanted into the GaN samples. As the emission pattern for nuclei in GaN is clearly distinct from that of nuclei in Ga2O3, the fraction of probe nuclei in the oxide layer can be directly measured and allows to follow the time dependent growth of the oxide on a scale of less than 100 nm.en620poster