PQI Seminar: David Eagles (Imperial College)

May 21, 2015 - 8:30pm to 10:00pm

Title: The first-discovered Bose-gas superconductor, and three small systems showing probable room-temperature superconductivity    
My talk will be about two different topics, but both involve unusual types of superconductivity. First I shall talk about my analysis in the late 1960’s of some work from Westinghouse on superconductivity in Zr-doped SrTiO3 with oxygen vacancies to produce current carriers. This work indicated that superconducting transition temperatures Tc in 3% Zr-doped samples were still rising as electron concentration n decreased at the lowest concentration they studied. My analysis of their data indicated that Tc could continue to rise as n decreased until Tc became limited by the Bose-condensation temperature of pairs rather than the pairing temperature. About 14 years later colleagues of mine in Australia were persuaded to start to try to test this prediction. We found evidence that one 3%-Zr doped ceramic sample was on the Bose-gas side of the BCS-Bose transition.
The second topic I shall discusss will be three small systems which I consider show probable room-temperature superconductivity. These systems are (1) narrow channels through films of oxidised atactic polypropylene, (2) some multiwalled or arrays of single-walled carbon nanotubes, and (3) thin films of boron-doped CdF2. Key experimental results in all these systems will be mentioned, but most emphasis will be on the first system, on which I have spent a good fraction of my time since 1993.
1 e-mail: d.eagles@ic.ac.uk
References on these two topics may be found in:
1. D.M. Eagles, R.J. Tainsh and C. Andrikidis, Physica C 157, 48 (1989).
2. D.M. Eagles, Physica C 483, 82 (2012).

Location and Address

321 Allen Hall