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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 (Note that this research has not been peer-reviewed or published yet.)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."
Magnetic levitation photos or it didn't happen.
-- Alastair
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.
The unfortunate reality is that *because of the scandal*, and under the current political fallout conditions, it is considered professional suicide to even get evolved with it. Any projects you are working on will immediately become unfunded, even those not directly related to Cold Fusion. The politics are a formidable problem with moving the technology forward, and that is not likely to change any time soon. Someday it will no longer be taboo to work on it, but for now don't hold your breath. Bad politics can kill almost any 'good thing' despite the clear benefits it might possess for the future. Right now the only way it will ever move forward is through private funding.
Superconductors tend to lose superconductivity in the presence of a large magnetic field, limiting the amount of current they can carry.
Type I yes. Type II no.
The latter makes current whirlpools that pinch the magnetic field into little quantized columns, which arrange themselves in a hexagonal grid. Superconduction quits in the narrow column where the mag field penetrates, but continues just fine in the rest of the material, dodging around the columns. The field must be very strong to make a lattice of mag field penetrations so dense that they merge and all superconduction crosswise to the mag field quits.
Not that it matters:
Superconductors are useful for a LOT of stuff besides carrying power around. Being able to make thin-film superconductor elements with a critical temperature, not just of an air conditioned room, but of a human body with a moderately high fever, would be very useful. (You could keep it cool enough to keep working, even inside a piece of hot equipment on a hot day, with a Peltier junction cooler. No problem.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Nothing you said is relevant except for the actual paper, which is well written (and doesn't read like a crank - he appears to be fully cognizant of the current state of the field). I've posted (elsewhere on this page) exactly why this conclusion is unlikely (based on a critique of the actual arxiv paper). Further, the author does not claim what the summary here states (another reason to RTFA) - he merely states that it may be an indication of superconductivity in the context of a specific model that was published a while ago (in a mainstream journal). You might want to take a minute to look into it before showing your ignorance with such ludicrous rants.