Using Corbino disk sample geometry to separate quasiparticle and vortex motion contributions to the mixed state dissipation of YBCO

Abstract

A method, using a Corbino disk sample geometry, is described and applied to study of resistive tails of sintered $YBCO$. When the transport current passes radially from the rim of the disk sample to its center, the two component potential drop signal is detected below $T_c$, which is due to (i) quasiparticles $W_q$ and (ii) vortex-core-motion related contribution $W_{\phi }$. When the contact pairs for $W$ are placed radially, $W_q(r)$ and $W_{\phi }(r)$ are found to follow the markedly distinctive functional dependences, providing a unique possibility to deconvolute the relative strengths of both contributions. The results obtained suggest that the mixed state dissipation of high-$T_c$ superconductors is strongly influenced by the quasiparticle excitations.