Fascinating Ceramics: Electronic Ceramics

When many people hear the word "ceramics," I think they probably picture "pottery and porcelain" or "the space shuttle's heat-insulating tiles" (Photo 1). You probably have an image of a "hard, heat-resistant material." However, among the family of ceramics, there are also those with properties such as conducting electricity, storing electricity, becoming magnetic, and generating electricity when pressure is applied. There are many types of ceramics that utilize these properties and are used as electrical components. These are called "electronic ceramics" or "electroceramics." Electronic ceramics have become indispensable for creating lightweight and small electronic products, and the miniaturization of mobile phones is one example of their success (Photo 2).

Improving the performance of electrical components is necessary to create the electronic appliances that enrich our lives, and electronic ceramics are no exception. The properties of ceramics are determined by their constituent elements and their quantities—in other words, their composition. Therefore, to create better ceramics, it is necessary to clarify the relationship between composition and properties. Based on this, appropriate "composition design (material design)" is carried out.

Most ceramics are polycrystalline bodies—aggregates of small crystal grains—but their properties also vary greatly depending on the state of aggregation of these grains (called the microstructure). Photo 3 shows ceramics with the same composition, but they have completely different microstructures depending on the manufacturing method, and their properties differ accordingly. Thus, to produce high-quality ceramics, an appropriate "fabrication process design (processing design)" is necessary.

Research on the fabrication of ceramics is conducted in the Department of Applied Chemistry. "Chemistry" is the academic discipline that primarily clarifies the "relationship between the structure and properties of matter" and the "changes in the state of matter." These two correspond to "material design" and "processing design," and chemistry methods are widely used in research to improve the properties of ceramics (Photo 4).