Hyperconductivity in fluorphlogopite at 300 K and 1.1 T

• Published in: Europhysics letters 2019-07, Vol.127 (1), p.16001
• Main Authors: Russell, F. Michael, Russell, Mark W., Archilla, Juan F. R.
• Format: Article
• Language: English
• Subjects: 63.20.kd; 63.20.Ry; 63.22.Np; Biotite; Crystal defects; Crystal dislocations; Current carriers; Defect annealing; Electric charge; Electric fields; Electrons; Mica; Muscovite; Silicates
• ISSN: 0295-5075; 1286-4854; 1286-4854
• DOI: 10.1209/0295-5075/127/16001

We report on studies of hyperconductivity in which electric charge moves in a solid in the absence of an applied electric field. This is indicative of a non-Ohmic mechanism. Our results are consistent with charge being carried ballistically by mobile nonlinear lattice excitations called quodons moving along close-packed atomic chains in the cation layers of some silicates. The finding that quodons can trap and carry a charge was first found by the authors in muscovite (Russell F. M. et al., EPL, 120 (2017) 46001), which previously was not possible. In this paper we have also found hyperconductivity in lepidolite, phlogopite and synthetic fluorphlogopite but not in biotite or quartz. We have found that a current continues to flow for many seconds after the creation of quodons is stopped, indicating they have long flight-paths. This shows that quodons are decoupled from phonons, must experience elastic reflection at boundaries and are not stopped by inevitable dislocations or other minor defects. We have also found that quodons can anneal defects caused by mechanical working of crystal faces. The current carried by quodons is unaffected by a magnetic field of 1.1 T.