Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

In Situ TEM investigations on thermoelectric Bi2Te3/Sb2Te3 multilayers

: Schürmann, U.; Winkler, M.; König, J.; Liu, X.; Duppel, V.; Bensch, W.; Böttner, H.; Kienle, L.


Advanced engineering materials 14 (2012), Nr.3, S.139-143
ISSN: 1438-1656
ISSN: 1615-7508
Fraunhofer IPM ()
thermoelectric; multilayer; transmission electron microscope; nanoalloying deposition; molecular beam epitaxy

In this work, the impact of heat treatment on the real structure of Bi2Te3/Sb2Te3 multilayers is investigated. The material was heated in situ in the transmission electron microscope (TEM) and ex situ inside a furnace after preparing these layers with the so-called nanoalloying deposition technique via molecular beam epitaxy (MBE) equipment. The samples were prepared as a lamella for TEM studies using focused ion beam technique. EDX elemental mapping and high angle annular dark field mode-STEM were performed to monitor changes of the morphology and interdiffusion phenomena after heating up to 250 °C. A grain growth started during heating and the chemical layer structure was smeared out partly but remained in several grains and was found to be adjusted parallel to a major lattice plan e in a crystallite. High resolution TEM shows polysynthetic twinning in a number of crystals.