Research

Aim of Research

Combinatorial and high-throughput approaches
- Development and application of electrode arrays, micro-hotplates and cantilever arrays in materials science

Conventional and ferromagnetic shape-memory-alloys
- Ternary and quarternary shape-memory-alloys with marginal hysteresis
- Influence of alloying elements of ternary and quarternary Ni-Ti-X-Y alloys
- Development of novel ferromagnetic shape-memory-alloys based on the Fe-Pd system
- Thin film to bulk scaling effects

Microengineering
- Development and application of micro-hotplates and electrode arrays in materials science
- Development of Microactuators based on shape-memory thin films

Next-generation energy materials, especially hydrogen research
- Combinatorial thin film libraries of novel hydrogen storage materials (complex metalhydrides)
- Solar-water splitting (metal oxynitrides)
- Fuel cell materials (catalysts, diffusion barriers)
- Lithium-ion battery materials (mechanical effects during lithiation)

Multifunctional nanocomposites
- Development of novel nanocomposite materials, incorporating sensor and protective coating mechanisms

Nanostructures and nanomaterials
- Examination of nanoscale thin films
- Fabrication of nanoscale thin film objects using the top-down approach

Integrity of small scale systems/High temperature materials (A. Ludwig: spokesperson of the Materials Research Department)
- MEMS-based systems for in situ observation of the integrity of small scale systems
- Development of multifunctional, microstructured oxide and nitride materials for application in harsh environments
  (e.g. high temperature, stress or corrosive environments)



























The idea of combinatorial materials science is to develop and use advanced materials fabrication methods which produce a large number of different materials on a substrate in one experiment under identical conditions.

After the combinatorial deposition process the material libraries are screened for desired physical properties by adequate high-throughput characterization tools. Most effectively the screening is performed by parallel (e.g. optical) or fast sequential methods.

By using the combinatorial materials science approach, an accelerated development of new materials can be expected.


Research

The research of the Chair MEMS Materials is based on the application of combinatorial thin film deposition methods and high-throughput characterization-tools. Beside the further development of combinatorial thin film deposition methods, the design and realization of new high throughput characterization tools is a goal of the CMS group. The new concepts for high throughput characterization are based on MEMS and nanotechnology approaches.

These methods are used in order to identify and optimize new materials, which are suitable for industrial applications. The group focuses on materials for microsystems (magnetic, shape memory) and materials for hydrogen storage.

Combinatorial thin film deposition methods

The fabrication of thin film libraries by combinatorial thin film deposition methods can be divided in several categories:

1. Precursor deposition method
2. Co-deposition method
3. Deposition of wedge type films

At the combinatorial materials science lab of the Chair MEMS Materials, a unique UHV combinatorial cluster sputter deposition system is used. It allows the usage of all three methods for depositing optimized materials libraries.

High-throughput characterization of materials libraries

After the deposition of a thin film library, the screening for spots which show the desired physical properties has to be performed in an effective way. Generally, parallel or serial screening methods for thin film libraries can be applied depending on the physical property which is measured.


In order to determine whether the materials on the library are crystalline or amorphous, or to distinguish different crystallographic phases, automated XRD (x-ray diffraction) is used. To clarify structure-property relations, samples for the analysis of the nanostructure in the TEM (transmission electron microscope) can be rapidly prepared by automated FIB (focused ion beam).


Special physical properties

An automated 4-point probe for the measurement of temperature-dependent magneto-electronic properties was developed.

It is used for Wafer-Mapping of:

- temperature dependent resistivity
- temperature dependent Kerr effect
- temperature dependent magneto-resistance


Furthermore several screening techniques based on MEMS wafers (cantilever-, membrane-, electrode-, micro-hotplate) are currently developed for combinatorial materials science experiments.


Links to fellow Research Groups and Cooperation Partners

USA:

Ichiro Takeuchi, University of Maryland, College Park, MD, USA

Jason Hattrick-Simpers, University of South Carolona, Columbia, SC, USA


Canada:

Jeff Dahn, Dalhousie University, Halifax, NS, Canada


Japan:

Toyohiro Chikyow, NIMS, Tsukuba, Japan


Europa:

Wilhelm F. Maier / Klaus Stöwe, Lehrstuhl für Technische Chemie (Universität des Saarlandes), Saarbrücken, Germany

Brian Hayden, Ilika, Southhampton, England

Ulrich S. Schubert, Lehrstuhl für Organische Chemie (FSU), Jena, Germany

Wolfgang Schrof, BASF, Ludwigshafen, Germany

Achim Walter Hassel, Institut für Chemische Technologie Anorganischer Stoffe(JKU), Linz, Austria

Jochen M. Schneider, Lehrstuhl für Werkstoffchemie (RWTH), Aachen, Germany

Dierk Raabe, Max-Planck Institut für Eisenforschung, Düsseldorf, Germany

Johan Paul, Flanders Materials Center (Flamac), Belgium