A study of vortex motion in YBa2Cu3Ox thin films as revealed by the simultaneous appearance of longitudinal and transverse voltages

We have carried out simultaneous measurement of longitudinal and transverse voltages which are generated when a YBa2Cu3Ox, thin film is subjected to m agnetic field (B) at an angle 0 to current (I), with both B and I parallel to the ab-plane. The measurements were made as a function of current and te mperature both above and below the vortex glass transition temperatures. Th ese studies have been helpful to differentiate between dissipation caused b y vortex motion in the direction of the Lorentz force and that caused by ot her mechanisms. The results for the first time show that the dissipation ca used by the Lorentz force has two components. Both the components show powe r law behavior. The first component is seen to increase sharply with the cu rrent and is attributed to vortex motion in the direction of the Lorentz fo rce. The second component has been attributed to vortex motion induced ther modynamical fluctuations in the order parameter. (C) 2001 Elsevier Science B.V. All rights reserved.