Take a copper plate, heat in oxygen half the material to convert to oxide,
roll the plate into a cylinder, heat and reform into a solid cylinder. The oxide folded inside should cool into crystals. Pull into a wire.
Test conductivity. DC and AC. The inner cylinder, the interface between copper and copper oxide should also exhibit skin effect for AC at high frequencies. Skin effects on the outside surface will be a delayed signal.
Is the wire superconducting?
