Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 53: Poster II

HL 53.33: Poster

Mittwoch, 9. März 2016, 09:30–13:30, Poster A

Optical and magnetic studies of MBE-grown ferromagnetic CrSe and CrS layers in zincblende structure — •Johannes Röder¹, Nico Hofeditz¹, Richard T Moug², Kevin A Prior², Dana Vieweg³, Hans-Albrecht Krug von Nidda³, Alois Loidl³, and Wolfram Heimbrodt¹ — ¹Department of Physics and Material Science Center, Philipps University, Marburg, Germany — ²Institute of Photonics and Quantum Sciences, SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK — ³Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany

Theoretical calculations predicted Chromium chalcogenides in the zinc blende (ZB) structure to be promising candidates for half-metallic spin-aligner at room temperature. Unfortunately, the thermodynamically stable phase of CrSe and CrS is the hexagonal NiAs-structure. Different approaches have been tested to stabilize the ZB state. Most promising were CrSe layers grown on GaAs substrates with either ZnSe or ZnSe/MgS as buffer layers and CrS-layers embedded between ZnMgS layers. All samples have been grown by MBE. We investigated the ferromagnetic properties and magnetic phase transitions and the respective optical properties of these films by temperature dependent SQUID and photoluminescence measurements. Ferromagnetic phase transitions have been found. The highest yet observed Curie temperature was at 255 K. Optical measurements revealed excitonic transitions, which will be discussed in detail.