Material synthesis

This research area encompasses the development and synthesis of dielectric, piezoelectric, and ferroelectric materials with homogeneous and textured microstructures for piezoceramics, capacitors, electrocaloric cooling elements, PTC heating elements, and other electroceramic applications.

Research in the field of piezoceramics focuses on the synthesis of environmentally friendly, lead-free piezoceramic materials and high-temperature materials. Current research focuses on the development of single-crystal templates for structuring both lead-free and lead-containing materials via film casting and fiber spinning processes, followed by texturing using the Templated Grain Growth (TGG) method. This significantly improves the piezoelectric properties of piezoceramic materials.

For miniaturized components with the highest power density, power electronics require capacitors with high capacitance density capable of withstanding high electrical voltages and temperatures. Only capacitors with such properties will meet future requirements in circuits using wide-bandgap semiconductors. To meet this demand, we are developing novel antiferroelectric capacitors that exhibit significantly higher permittivities at higher electric fields compared to conventional capacitors, thereby enabling an increase in energy density.

Ceramic PTC (positive temperature coefficient) materials exhibit a sudden increase in electrical resistance as the temperature rises. They are used for overcurrent protection, as temperature sensors, or in PTC heaters. In battery-electric vehicles, PTC components can be used both as air heaters and for battery temperature control. The increase in the vehicle electrical system voltage to 800 V raises new questions and places new demands on PTC components – particularly regarding their breakdown voltage – which we are addressing in our research projects.

To develop active cooling elements – primarily for power electronics, but also for novel air conditioning systems – we are pursuing the development of electrocaloric materials based on ferroelectric relaxor materials. Through careful selection of stoichiometry and doping, the phase position and thus the operating temperature are adjusted. This enables the creation of particularly environmentally friendly and efficient cooling systems. 

 

Services offered

 

• Synthesis of novel dielectric, piezoelectric, and ferroelectric materials for piezoceramics, capacitors, PTC heating elements, electrocaloric cooling elements, and other electroceramic applications 
• Characterization of the dielectric, piezoelectric, and ferroelectric small-signal and large-signal properties under application-relevant operating conditions

 

Technical equipment

 

• Powder processing: planetary ball mill, agitator ball mill, laboratory mortar mill, vibrating micro mill, oscillating mill
• Hydrothermal synthesis
• Compaction processes: uniaxial, isostatic (CIP, HIP)
• Heat treatment: laboratory chamber furnaces, vacuum-oxygen furnace, high-temperature furnace for N₂/H₂ atmosphere