Sustainable magnetostrictive thin filmsWednesday (07.06.2017) 20:00 - 20:03 Förde I Part of:
Rapid progress in nanorobotics and MEMS/NEMS devices lead to an increasing demand for smart functional materials in sensor and actuator application. Strong utilisation of magnetic fields in such devices renders magnetostrictive materials particularly important for their development. Existing high-performance materials such as Terfenol-D (TbxDy1-xFe2 x~0.3) and Galfenol (Fe-Ga), however, often do not meet mechanical requirements or are made out of critical raw materials; current global concerns such as shortage of resources, restricted choice in sources of import as well as environmental and health issues thus often impede the broad development and implementation of novel devices. The Fe-Al system is a promising sustainable alternative to these materials. Its well-known bulk magnetostrictive properties perform on the same order of magnitude as the closely related Fe-Ga system at a fraction of its price. However, comparatively little research has been dedicated to the development of magnetostrictive Fe-Al thin films so far. The current study is aimed at the investigation of such films and the improvement and specific tailoring of their properties. Strategies such as metastable phases produced by magnetron sputtering, induced phase transformations and ternary alloying are presented. Results on respective binary and ternary Fe-Al alloy thin films are given and put in a broader context. Finally, further applications in device materials are suggested.