CORRELATION OF IRREVERSIBILITY AND VORTEX SOLID MELTING FOR TLNBA2CA2CU3OX (N=1, 2) THIN-FILMS

The transport measurements were performed for the TlnBa2Ca2Cu3Ox (n = 1, 2) thin films in magnetic fields. The resistive state could be appr oximately described by the thermally activated form, rho similar to ex p[-U(H,T)/k(B)T], where U(H,T) proportional to (const. + T)H--alpha wi th alpha approximate to 0.5 similar to 0.6. This form, however, apprec iably deviates from the data for low dissipation and high fields. As f or the viscosity of the supercooled liquid, the divergence of U well d escribed the behavior, particularly, of the low dissipation state for all fields, implying the presence of the vortex solid. The log(V) - lo g(I) characteristics revealed the curvature change, which defines the vortex solid (glass) - liquid melting temperature T-m. Both the irreve rsibility line and the melting line showed approximately the same T de pendence, H-alpha similar to T-1, which is from the thermally activate d form. This correlation suggests that the irreversibility line approp riately figures the vortex solid (glass) - liquid melting line.