New ceramics for electronics and power engineering

28.06.2023

New ceramics for electronics and power engineering

Jurij Koruza and his team are working on ceramics used in electronics. The team is part of a new, highly funded collaborative research center led by Technical University Darmstadt.

Collaborative Research Center "FLAIR

Electroceramics are at the heart of many electronic components. A cell phone, for example, contains 500 capacitors consisting of several layers of ceramic and metal. “In ceramics, we can very well and specifically set properties that the material must have for the particular application,” explains TU Graz materials scientist Jurij Koruza, from the Institute of Chemical Technology for Materials at Technical University Graz. “And they can also be used at high temperatures and other harsh conditions.”

When we talk about “ceramics” at TU Graz, we are not talking about ceramics in the conventional sense – i.e. as a material for plates, cups and other tableware. Rather, we are talking about so-called functional ceramics, which are designed to fulfill certain tasks – some are particularly conductive, for example, or can catalyze reactions. In Jurij Koruza’s team, the researchers are particularly concerned with dielectrics and piezoceramics that can store electrical charge or convert mechanical energy into electrical energy. One example of this is modern ultrasound devices that are used in medical technology for imaging or in industry for environmentally friendly cleaning. In the future, however, these electroceramics could also be used as a power source for sensors that are placed in inaccessible locations but continuously receive mechanical energy from ambient vibrations and convert it into electrical charge – for example, under a road or in a tunnel wall.

Collaborative Research Center “FLAIR

Together with four German universities and 13 research teams led by the TU Darmstadt, researchers from Graz launched a new project in mid-May to study electroceramic materials. The Collaborative Research Center SFB 1548 (“FLAIR” – Fermi Level Engineering Applied to Oxide Electroceramics) is funded by the DFG (German Research Foundation) and the FWF (Austrian Science Fund) with a total of 10 million euros for four years – with the option of extension up to a total project period of 12 years. The aim of the large-scale project is to develop an accurate method for the design of certain functional ceramics and, above all, the targeted prediction of the expected properties. The so-called Fermi-level engineering, which is already used today in the semiconductor industry for the production of high-performance silicon chips, is being borrowed. The research consortium now wants to apply this principle to ceramics. “In the first four years of the project, we will lay the foundation for the new design concept, investigate model materials, test dopants and build up a database, which will then enable the development of completely new compositions in a next step, also with the help of computers,” Koruza explains. In possible further project phases, the team then also wants to focus on applications.

"The heart is the material"

In Graz, the focus will be on the company’s own special field, dielectrics and piezoceramics. For this purpose, ceramic samples are produced by means of solid-state synthesis and doped with different elements in order to specifically change the Fermi level and the defect states. The material is then painted and shaped into the desired form using various processes, such as pressing or 3D printing. After thermal treatment at over 1,000 degrees Celsius, the electroceramics are then given the desired crystal structure, microstructure and defect concentration, which together determine the electrical properties.

Lead-free materials

In addition to the new collaborative research center, the research team is committed to the topic of environmentally compatible materials in electronics. Many electroceramic materials and components today contain lead – a toxic heavy metal. But it is also a heavy metal that is very inexpensive and can be used universally. When used, lead in ceramics is not dangerous to users or the environment because of its stability. The problem, however, is final disposal: Many of our electronic components are not properly disposed of or recycled. Instead, they often end up in unsecured landfills, where they decompose over time, releasing the lead. That’s why researchers are scrambling to find a viable substitute for lead. In a recent paper in Nature Communications, “Tailoring high-energy storage NaNbO3-based materials from antiferroelectric to relaxor states,” Jurij Koruza and his team present just such a material. So there are promising material compositions, the researcher says. But: “Lead is universally applicable. The substitute materials that are being developed are not – they have to be specifically designed for the particular application. So, of course, production is much more costly because companies suddenly have to deal with many materials instead of one.”

Heart

But the researchers are still at it. Because: “In many new applications, it’s not the technology that’s at the heart, but the material. Because the material is responsible for the function – as in solar cells, fuel cells or batteries.”

Contact

Veronika Pranger

Green Tech Valley Cluster