A study of the oxide grown on Tb and terbium silicide by XPS, AES and XRD

Pure Tb as well as TbSi1.7/Si(100) were oxidized at 600°C for 30 min at atmospheric pressure. Auger, XPS and XRD spectra of the samples were measured before and after oxidation. The XRD results show that pure Tb oxidizes to form TbO1.81 while the oxide layer of the oxidized TbSi1.7 consists of Tb2SiO5. During sputtering of the Tb2SiO5 layer, Auger spectra show that Tb and not Si is oxidized, while the XPS spectra show that Tb as well as Si are oxidized as expected from the XRD results.