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DS: Fachverband Dünne Schichten
DS 33: Focus session: Resistive Switching by Redox and Phase Change Phenomena IV (Kinetic in oxides and phase change)
DS 33.4: Talk
Wednesday, April 2, 2014, 17:30–17:45, CHE 89
Optical and structural dynamics of the phase transition of GST phase change materials — •Lutz Waldecker1, Timothy Miller2, Roman Bertoni1, Simon Wall2, and Ralph Ernstorfer1 — 1Fritz-Haber-Institut der MPG, Berlin, Germany — 2ICFO - Institut de Ciències Fotòniques, Castelldefels (Barcelona), Spain
The phase change material Ge2Sb2Te5 (GST) exhibits large changes in its optical properties across the structural phase transition between its amorphous and crystalline phases. We investigate the transient behavior of the optical properties of GST after laser excitation below and above the threshold for persistent switching of the crystalline phase of the material by applying femtosecond transient reflectivity spectroscopy. In addition, we measure the electron-lattice coupling with time-resolved electron diffraction for separating electronic from structural contributions to the optical response. The combination of these two techniques allows for investigating the correlation between structure and function and addressing the question whether the phase transition is driven thermally or non-thermally.