Room-temperature superconductor
A room-temperature superconductor is a hypothetical material capable of displaying superconductivity above 0 °C (273 K; 32 °F), operating temperatures which are commonly encountered in everyday settings.
[6] In 2014, an article published in Nature suggested that some materials, notably YBCO (yttrium barium copper oxide), could be made to briefly superconduct at room temperature using infrared laser pulses.
[1][2] In 1993 and 1997, Michel Laguës and his team published evidence of room temperature superconductivity observed on MBE deposited ultrathin nanostructures of BiSrCaCuO.
[12][13] These compounds exhibit extremely low resistivities orders of magnitude below that of copper, strongly non-linear I(V) characteristics and hysteretic I(V) behavior.
[19] In 2012, an Advanced Materials article claimed superconducting behavior of graphite powder after treatment with pure water at temperatures as high as 300 K and above.
In 2018, Dev Kumar Thapa and Anshu Pandey from the Solid State and Structural Chemistry Unit of the Indian Institute of Science, Bangalore claimed the observation of superconductivity at ambient pressure and room temperature in films and pellets of a nanostructured material that is composed of silver particles embedded in a gold matrix.
[21] Due to similar noise patterns of supposedly independent plots and the publication's lack of peer review, the results have been called into question.
[46] Though the exact critical temperature has not yet been determined, weak signs of a possible Meissner effect and changes in magnetic susceptibility at 250 K may have appeared in early magnetometer tests on an original now-lost sample.
In 2016, research suggested a link between palladium hydride containing small impurities of sulfur nanoparticles as a plausible explanation for the anomalous transient resistance drops seen during some experiments, and hydrogen absorption by cuprates was suggested in light of the 2015 results in H2S as a plausible explanation for transient resistance drops or "USO" noticed in the 1990s by Chu et al. during research after the discovery of YBCO.
[52][53] It is also possible that if the bipolaron explanation is correct, a normally semiconducting material can transition under some conditions into a superconductor if a critical level of alternating spin coupling in a single plane within the lattice is exceeded; this may have been documented in very early experiments from 1986.
The best analogy here would be anisotropic magnetoresistance, but in this case the outcome is a drop to zero rather than a decrease within a very narrow temperature range for the compounds tested similar to "re-entrant superconductivity".
