Electroceramics Lecture Note

Electroceramics can be defined as ceramic materials which are able to perform an electronic function for a particular application. This rather wide umbrella-term includes materials for a wide range of applications, of varying complexity, from relatively simple insulating materials, to complex ferroelectrics. The materials for such applications are usually prepared from specifically formulated compositions (typically not found in nature), and processed under strictly controlled conditions. Some of the materials and applications are described below:

Dielectric (Insulating) materials

Most ceramics, and indeed electroceramics, are electrically insulating in nature; they resist the flow of current and are able to separate charge as a result. This allows ceramics to be used:

• as simple insulating materials, e.g. Al₂O₃
• in capacitors (e.g. BaTiO₃ ), where temperature stability/reproducibility are important
• as printed circuit board substrates (e.g. BeO, Al₂O₃ ), where thermal conductivity is a major factor
• as microwave resonant cavities (e.g. ZrTiO₄ ), facilitating both the reduction in size and increase in available lines for satellite and mobile phone communication systems.