Frequency response of AC susceptibility in high temperature superconductors

• Published in: Solid state communications Vol. 135; no. 3; pp. 203 - 207
• Main Authors: Liu, S.L., Wu, G.J., Xu, X.B., Wu, J., Shao, H.M., Jin, X.C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2005; Elsevier
• Subjects: A. Y-Based cuprates; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cuprates superconductors (high tc and insulating parent compounds); D. AC susceptibility; D. Vortex glass transition; Exact sciences and technology; Magnetic properties and materials; Physics; Properties of type I and type II superconductors; Superconductivity; Vortex lattices ,flux pinning, flux creep; D. Vortex glass transition; 74.25.Fy; 74.72.Bk; D. AC susceptibility; 74.60.Ge; A. Y-Based cuprates; Electrical conductivity; Vortex glass; Magnetic field effects; t-J model; 74.72.Bk A. Y-Based cuprates; Cuprates; Magnetic susceptibility; Glass transition; Ordered systems; Temperature effects; Barium oxides; High-Tc superconductors; Germanium; Quaternary compounds; Copper oxides; Activation energy; Yttrium oxides
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2005.03.069

Based on the thermal activation, considering the two most important energies, namely thermal activation energy, which drives the system to a more disordered state, and effective pinning energy, which keeps the system in order, a general description of the temperature dependence of resistivity under magnetic fields for high temperature superconductors has been deduced. The temperature dependence of resistivity can be expressed as ρ= ρ n (1− x) s , with the energy ratio x= U eff( T, B, J)/ k B T. This extended thermally activated model is a consistent description of the vortex glass theory. Our model is applied to the frequency response of AC susceptibility in YBCO superconductors; the results are in good agreement with the proposed model.