|Prof. Dr.-rer. nat. Gerold A. Schneider, Dr.-Ing. Rolf Janssen
|M.Sc. Henry Mgbemere, Dipl.-Ing. Tobias Stegk
High-Throughput Experimentation (HTE) techniques have gained wide acceptance in materials science in recent years. HTE allows for material samples to be synthesized and analysed in an automized, highly accelerated sequential way, avoiding the tedious and error-prone one-at-a-time-approach in the case of large systems under investigation.
The Advanced Ceramics Group has at its disposal a dosing robot for dry powders that allows the production of various ceramic systems and additionally various concentrations of each system in the form of single specimen in HTE mode starting from the raw powder state. These samples can be analysed by miscellaneous modes of Scanning Force Microscopy and also X-Ray Diffraction (XRD). Additionally various electrical parameters can be investigated using a custom-made analytical tool. All means of analysis can accommodate the large amount of samples produced by HTE-synthesis and the resulting analytic data.
A material system under amplified investigation is sodium potassium niobate (K0.5Na0.5NbO3, KNN) that holds the promise to be a leadfree replacement for lead zirconate titanate (PZT) which is in abundant use e.g. in the automotive industry. Just like PZT, KNN features special phase boundaries, so-called morphotropic phase boundaries (MPB) which allow for maximum piezoelectric behaviour. The HTE setup is used to examine known MPBs with respect to best piezoelectric coefficient as well as optimal Curie temperature. The setup also allows for the scanning of unknown concentration space with a view to finding potential new MPBs..
|Fig. 1: Powder dosing robot
|Fig. 2: High-throughput compatible XRD with area detector (GADDS)
Fig. 3: Injection valve for Diesel engine. The piezo actuator module is still fabricated from PZT ceramics which contains toxic lead.
Tobias A. Stegk, Rolf Janssen, and Gerold A. Schneider, "High-Throughput Synthesis and Characterization of Bulk Ceramics from Dry Powders",
J. Comb. Chem., 10 (2), 274–279, 2008.