An investigation on the effects of yttrium on the flux motion in Bi2Sr2CaCu2O8+δ thin film

Abstract

The effects of Y-doping on the flux motion in Bi₂Sr₂Ca_1−xY_xCu₂O_8+δ thin film, was investigated using magnetoresistance measurements at different temperatures and applied magnetic fields. The rate of dissipation or the appearance of finite magnetoresistance due to flux motion increases with applied magnetic field. However, Y doping decreases the rate of dissipation. This observation suggests that Y-doping prevents flux motion by improving the coupling strength between the CuO₂ planes. The strong intra-pancake coupling dominates the interpancake interaction at lower temperature regime leading to an attractive interaction between pancakes. As a consequence, vortex motion of the pancake stack is restricted and thus reducing dissipative energy.