Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 14: Poster
DS 14.57: Poster
Dienstag, 2. April 2019, 17:00–20:00, Poster E
Study of the in-plane lattice constant of phase change materials during deposition — •Hetal Vaishnav1, Marvin Kaminski1, Marc Pohlmann1, and Matthias Wuttig1,2 — 1I. Institute of Physics, Physics of New Materials, RWTH Aachen University, 52056 Aachen, Germany — 2JARA-Insitut Energy-efficient information technology (PGI-10), FZ Jülich, 52428 Jülich, Germany
Phase change materials (PCMs) are higher order chalcogenides which can be rapidly switched between the amorphous and crystalline state upon heating. The unique properties of the crystalline phase of these chalcogenides have recently been attributed to a novel bonding mechanism which we have coined metavalent bonding (MVB). In this bonding mechanism the electrons are on the verge of delocalization. This immediately raises the question how these materials behave in reduced dimensions such as thin films, where electron delocalization is impeded. To answer this question, thin films of different chalcogenides have been grown by molecular beam epitaxy (MBE). In the literature, two unexpected observations have been reported for GeTe thin films. For certain substrates, an increased in-plane lattice constant was observed for thin films, which reached the bulk value for thicker films. For other substrates, a transition from an amorphous to a crystalline state has been observed at a thickness of a few bilayers. These findings cannot be directly explained by strain effects or pseudomorphic growth. Hence, in this work, further investigations for different materials like SnTe and Sb2Te3 will be presented and compared to GeTe thin films.