title: Influence of Si and N additions on structure and phase stability of Ge(2)Sb(2)Te(5) thin films.
abstract: The influence of Si and N in Ge(2)Sb(2)Te(5) (space group [Formula: see text]) on structure and phase stability thereof was studied experimentally by thin film growth and characterization as well as theoretically by ab initio calculations. It was found that Si and N most probably accumulate in the amorphous matrix embedding Ge(2)Sb(2)Te(5) grains. The incorporation of Si and N in these samples causes an increase of the crystallization temperature and the formation of finer grains. N is more efficient in increasing the crystallization temperature and in reducing the grain size than Si which can be understood based on the bonding analysis. The incorporation of both Si and N in Ge(2)Sb(2)Te(5) is energetically unfavourable, leading to finer grains and larger crystallization temperatures. While in the case of Si additions no significant changes in bonding are observed, N additions appear to enable the formation of strong Te-N bonds in the amorphous matrix, which are shown to be almost twice as strong as the strongest bonds in unalloyed Ge(2)Sb(2)Te(5).
authors.affiliation: Materials Chemistry, RWTH Aachen University, D-52056 Aachen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Kölpin
authors.forename: Denis
authors.initials: D
authors.lastname: Music
authors.forename: Galyna
authors.initials: G
authors.lastname: Laptyeva
authors.forename: Reza
authors.initials: R
authors.lastname: Ghadimi
authors.forename: Florian
authors.initials: F
authors.lastname: Merget
authors.forename: Silvia
authors.initials: S
authors.lastname: Richter
authors.forename: Ruslàn
authors.initials: R
authors.lastname: Mykhaylonka
authors.forename: Joachim
authors.initials: J
authors.lastname: Mayer
authors.forename: Jochen M
authors.initials: JM
authors.lastname: Schneider