Nitrogen contribution to N-doped GeTe (N: 8.4 at.%) in the structural phase transition

Abstract

Chemical states of N-doped GeTe (N: 8.4 at.%) thin film (NGT) in structural phase transition were investigated by near-edge x-ray absorption of fine structure and high-resolution x-ray photoelectron spectroscopy with synchrotron radiation. We found the NaCl-like structure in NGT by x-ray diffraction at around 300 degrees C. Preparatory to the analysis of chemical states, after mild Ne+ sputtering we obtained clean amorphous NGT, which showed the N-2 vibration mode peak in the N K-edge absorption spectrum. After annealing, the N-2 molecular peak disappeared completely and we assumed that nitrogen was contributed only to the Ge atom in structural phase transition by analyzing Ge 3d and Te 4d core-levels.