Positive temperature co-efficient of resistivity materials (PTCR) are a family of semiconductors that exhibit special properties concerning electrical conductivity. In particular, their electrical ...

Physicists have discovered surprising changes in electrical resistivity in iron-based superconductors. The findings offer further evidence that magnetism and superconductivity are closely related in ...

Since their first discovery in 1911, superconductors — materials which perfectly conduct electricity — have long beguiled and tantalized physicists. Superconductors are used in particle accelerators, ...