Nernst effect in Tl-Ba-Ca-Cu-O high-Tc superconducting thin films

Abstract

The dynamical behavior of magnetic flux in superconducting Tl-Ba-Ca-Cu-O films has been studied using the Nernst effect. Large temperature gradients of ∼105 K/cm and, correspondingly, large thermal forces on flux lines were obtained by pulsed laser heating of films. Due to the large thermal driving forces it was possible to observe, at temperatures well below Tc, the transition from thermally assisted flux flow to flux creep and viscous flux flow.