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oai:docta.ucm.es:20.500.14352/596482024-08-30T14:55:09Zcom_20.500.14352_14col_20.500.14352_15

Crossover from a three-dimensional to purely two-dimensional vortex-glass transition in deoxygenated YBa_(2)Cu_(3)O_(7-δ) thin films Sefrioui, Zouhair Arias Serna, Diego Villegas, J. E. Varela Del Arco, María López de la Torre, M. A. León Yebra, Carlos Loos, G. D. Santamaría Sánchez-Barriga, Jacobo 537 High-temperature superconductors Lattice-melting transition Solid phase-transition Thermal fluctuations II superconductors Boson localization Universality Resistivity Transport Disorder. Electricidad Electrónica (Física) 2202.03 Electricidad © 1999 The American Physical Society. Z.S. gratefully acknowledges financial support from Agencia Española de Cooperación International (AECI). G.D.L. thanks the sabbaticals SA 106/95 SAB1995-0685 to Universidad Complutense and Ministerio de Educación y Cultura. Financial support from CICYT Grant No. MAT94- 0604 is also acknowledged. We thank Professor J. L. Vicent for helpful discussions. Current-voltage (I-V) characteristics were used to investigate the response of the vortex-glass (VG) phase transition in high-quality epitaxial YBa_(2)Cu_(3)O_(7-δ) films in magnetic fields up to 7 T. We show that varying the oxygen content, the scaling analysis reveals a crossover from three-dimensional (3D) to a pure 2D VG transition with T_(g) = 0. At small oxygen deficiencies (7-δ = 6.75), the ρ-j curves scale according to the 3D VG model, which cannot be distinguished from a Bose-glass model from a scaling analysis with the magnetic field applied parallel to the c axis. At a lower oxygen content (7-δ = 6.48), the VG phase transition behaves analogous to the highly anisotropic Bi_(2)Sr_(2)CaCu_(2)O_(8) samples, showing a quasi-2D VG transition. For further deoxygenated samples (7-δ = 6.4), the result is consistent with a pure 2D vortex-glass model similar to that observed in the even more anisotropic Tl_(2)Ba_(2)CaCu_(2)O_(8) thin films. The estimated value of the anisotropy in high-quality oxygen-depleted samples is comparable to that of the highly anisotropic superconductors. Agencia Española de Cooperación International (AECI) Universidad Complutense Ministerio de Educación y Cultura CICYT Depto. de Estructura de la Materia, Física Térmica y Electrónica Fac. de Ciencias Físicas TRUE pub 2023-06-20T20:08:10Z 2023-06-20T20:08:10Z 1999-12-01 journal article https://hdl.handle.net/20.500.14352/59648 1098-0121 10.1103/PhysRevB.60.15423 eng SA 106/95 SAB1995-0685 MAT94-0604 open access application/pdf American Physical Society