Certain doped-oxide ceramics resist Ohm's Law

Certain doped-oxide ceramics resist Ohm's Law: Several of the slightly doped high-purity barium titanate (BT) ceramics his research group was investigating were not following the venerable Ohm's Law, which relates electrical voltage to current and resistance. Applying or removing a voltage caused a gradual change in the materials' electrical resistance. The new effect was seen consistently regardless of the temperature or whether the experiments were conducted in vacuum, air, or in an oxygen atmosphere. The time to stabilize and the final, steady-state resistance were, however, both temperature-dependent.

"I was not immediately convinced myself about the non-Ohm's Law behavior," said West, Professor of Electroceramics and Solid State Chemistry at the University of Sheffield in England. "Interfacial effects are well known for their non-Ohmic behavior. We needed to be really convinced that our results were not influenced in some way by interfacial effects."