Bulletin Spring‧Summer 1994

Ceramics THINNER than a Wafer Ceramic Thin Films Diverse Uses of Ceramics Ceramics and porcelain are some of the oldest examples of material technology: when clay is baked under suitable conditions, it turns into a hard, strong, and heat resistant substance. Because they are hard, and remain hard at high temperatures, ceramics are used in modem times as abrasives and cutting tools. And as they are extremely heat resistant, ceramic tiles are used in the lining of metal refineries, and o f the nose cones of space shuttles, which bear the brunt of the damage as the shuttles return to earth, generating extreme heat due to friction with the atmosphere. Chemically, ceramics are oxides, and as such are usually extremely poor conductors of electricity. Thus they are used as insulators in high voltage transmission lines. But ceramics gained sudden fame a few years ago in the world of physics, when some of them were found to be — to everybody's utter surprise — not insulators at all, but superconductors. Research Projects 11