Hall coefficients and resistivities of YBa2Cu3Oy films in super-conducting mixed state have been measured at T near Tc. A sign reversal of Hall coefficients in superconducting mixed state is accounted for in terms of the induced electric field, Eind = B × vL/c. Eind occurs as a result of the motion of the flux-vortex; B the magnetic induction; vL the resultant velocity of the flux vortex; and c the speed of light. The normal carriers were driven to one side of the sample by the transverse component Eind,y (perpendicular to the transport current js). In a steady state, an electric field Eacc, yx would be developed by the accumulated charge carriers and the direction of the Eacc, yx is opposite to that of the Hall electric field in the normal state. A sign reversal of Hall coefficient would occur if Eacc, yx dominates in the transverse electric fields. This picture explains both p-type and n-type superconductors.
ASJC Scopus subject areas
- 化學 (全部)