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Possible Room Temperature Superconductor Achieved
TechkNighT_1337 sends news that surfaced on the Next Big Future blog, concerning research out of the University of Bengal, in India. The report is of a possible superconducting effect at ambient room temperatures. Here is the paper on the ArXiv. (Note that this research has not been peer-reviewed or published yet.) "We report the observation of an exceptionally large room-temperature electrical conductivity in silver and aluminum layers deposited on a lead zirconate titanate (PZT) substrate. The surface resistance of the silver-coated samples also shows a sharp change near 313 K. The results are strongly suggestive of a superconductive interfacial layer, and have been interpreted in the framework of Bose-Einstein condensation of bipolarons as the suggested mechanism for high-temperature superconductivity in cuprates. ... The fact that the results described above have been obtained from very simply-fabricated systems, without the use of any sophisticated set-up and any special attention being given to crystal purity, atomic perfection, lattice matching, etc. suggests that the physical process is a universal one, involving only an interface between a metal and an insulator with a large low-frequency dielectric constant. We note in passing that PZT and the cuprates have similar (perovskite or perovskite-based) crystal structures. This resemblance may provide an added insight into the basic mechanism of high-temperature superconductivity."
Yes, but the small crystals are usually a side-effect of the technique used to find novel superconducting compounds. What some groups do is create polycrystalline lumps where each crystal has a slightly different formula. Then they test resistivity with changing temperature across the whole lot. If just one crystal superconducts, there will be a 'kink' in the graph. This is like a simple brute-force method for testing many samples in parallel, but doesn't necessarily provide a formula that an be produced in bulk.
It's like a mathematical proof that states that something "must exist" without providing an actual value.
Also, superconductors are inherently useful irrespective of the current carrying capacity. For example, Josephson Junctions and RSFQ digital electronics are both very useful and require very low power.
Even a "thin-film" superconductor like the one described in the article would be very useful, as that can be practical for integrated circuitry, even if it's not possible to make a flexible wire out of it.