RT Journal Article T1 Vortex liquid entanglement in irradiated YBa_(2)Cu_(3)O_(7) thin films A1 Sefrioui, Zouhair A1 Arias Serna, Diego A1 González Herrera, Elvira María A1 León Yebra, Carlos A1 Santamaría Sánchez-Barriga, Jacobo A1 Vicent López, José Luis AB Epitaxial YBa_(2)Cu_(3)O_(7) thin films, grown by high-pressure dc sputtering, are irradiated with He^(+) ions at 80 keV with doses between 10^(14) and 10^(15) cm^(-2). Irradiation reduces the critical temperature but it does not modify the carrier concentration. Angle-dependent resistivity is used to show that the mass anisotropy does not change upon irradiation. The melting transition in magnetic fields applied parallel to the c axis is analyzed by I-V critical scaling, and all irradiated and nonirradiated samples show a three-dimensional vortex glass transition with the same critical exponents. The dissipation in the liquid state is analyzed in terms of the activation energy of the magnetoresistance in a perpendicular magnetic field. While as-grown samples show an activation energy depending as 1/H on the applied magnetic field, irradiated samples show a dependence as 1/H^(0.5), characteristic of plastic deformation of vortices. This is discussed in terms of the point disorder introduced by ion irradiation. PB American Physical Society SN 0163-1829 YR 2001 FD 2001-01-18 LK https://hdl.handle.net/20.500.14352/59641 UL https://hdl.handle.net/20.500.14352/59641 LA eng NO © 2001 The American Physical Society. Financial support from CICYT Grant Nos. MAT94-0604, MAT97-0675, and MAT99-1706E is acknowledged. Z.S. thanks AECI for financial support. NO CICYT NO AECI DS Docta Complutense RD 8 abr 2025