Investigation of phase transition of Ge 2 Sb 2 Te 5 and N-incorporated Ge 2 Sb 2 Te 5 films using x-ray absorption spectroscopy

• Published in: Applied physics letters 2008-02, Vol.92 (6), p.061910-061910-3
• Main Authors: Kim, Youngkuk, Jang, M. H., Jeong, K., Cho, M.-H., Do, K. H., Ko, D.-H., Sohn, H. C., Kim, Min Gyu
• Format: Article
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2844878

For this study, the phase-change materials Ge 2 Sb 2 Te 5 and N-doped Ge 2 Sb 2 Te 5 films were investigated using x-ray absorption near-edge structure and extended x-ray absorption fine structure. During the phase transition, change in electronic structure is observed by the shift of the absorption edge energy, i.e., structural coordination of Ge-Te changes from tetrahedral to octahedral coordination, of which the interatomic distances are 3.12 and 2.83 Å , respectively. In addition, nitrogen incorporation into the film led to a p - p orbital hybridization and a different crystallization behavior. The hybridization caused by the formation of a Ge-N bond was related to suppression of the phase transition.