Piezotronic effects in freestanding microcomposites

• Applicants: Professor Dr. Rainer Adelung; Professor Dr. Lorenz Kienle; Privatdozentin Dr. Bridget Murphy
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2015 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269936415

In this project, we adopt a new approach to developing highly sensitive magnetic field sensors via piezotronic effects. In addition to a fundamental understanding of piezotronic concepts for magnetoelectric (ME) sensors a significant increase in sensitivity as compared to the current status. The sensors consist of freely standing composite structures consisting of a magnetostrictive and a piezoelectric component. One dimensional ZnO micro- and nanostructures with high aspect ratios will be employed due to their extensive experience of the proponents with these materials. In order to allow custom design of ZnO crystals meeting the requirements for piezotronic applications a new flame transport synthesis will be used. Due to the strong dependence of piezotronic properties on morphology, defects, crystal quality, interfaces, and local deformation behaviour an exact knowledge of these structural properties on a range of different length scales is required. The existing synergy between the applicants in the area of crystal growth and in situ characterisation by electron microscopy and micro X-ray diffraction will be built upon in this project. These complimentary characterisation methods together provide the possibility to perform spatially resolved structural analysis with the highest precision from the micron through nanometre down to atomic length scales. Highly challenging aspects are the planned method development for in situ electron microscope and operando X-ray scattering experiments. Due to the parallel characterisation of structural, electronic, and electrical properties it will be possible to engineer piezotronic biased MS sensors delivering previously unattainable high levels of sensitivity. The understanding obtained in this project will provide a foundation for knowledge transfer to other systems such as AIN biased ME sensors.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Olaf Magnussen