Room-temperature superconductor

A room temperature superconductor is material yet to be discovered which would be capable of exhibiting superconducting properties at temperatures above 0°C (273.15 K). This is of course not strictly speaking "room temperature" (20–25°C), however it can be reached very cheaply even for large machines (for example, meat closets reach this temperature).

Since the discovery of high-temperature superconductors, several materials have been claimed as being room-temperature superconductors. In every case, independent investigation has quickly proven these claims false. As a result, most condensed matter physicists now welcome with extreme skepticism any further claims of this nature.

As of 2006, the highest-temperature superconductor (at ambient pressure) is mercury thallium barium calcium copper oxide (Hg_0.8Tl_0.2Ba₂Ca₂Cu₃O_8.33), at 138 K, though there are claims that this can be raised to 164 K by applying high pressure to the superconductor.

Ultraconductors are not called superconductors because they do not exhibit the Meissner effect. However, if they exist, they would have many of the other characteristics of a superconductor. Since this phenomenon has not been widely duplicated it is still regarded by many scientists with skepticism.