2016/12/16 by А. В. Кузнецов, Kuznetsov, A. V., I. I. Sanninkov +3
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Field Sensors Techniques #Magnetic and transport properties of perovskites and related materials #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.1612.05454
openalex publication_date 2016/12/16 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
Combined action of weak and strong pinning centers on the vortex lattice complicates magnetic behavior of a superconductor since temperature and magnetic field differently affect weak and strong pinning. In this paper we show that contributions of weak and strong pinning into magnetization of the layered superconductor YBa2Cu3O7-δ can be separated and analyzed individually. We performed a careful analysis of temperature behavior of the relaxed superconducting current J in YBa2Cu3O7-δ films which revealed two components of the current J = J1 +J2. A simple method of separation of the components and their temperature dependence in low magnetic fields are discussed. We found that J1 is produced by weak collective pinning on the oxygen vacancies in CuO2 planes while J2 is caused by strong pinning on the Y2O3 precipitates. J1 component weakly changes with field and quasi-exponentially decays with temperature, disappearing at T ≃ 30--40~K. Rapid relaxation of J1 causes formation of the normalized relaxation rate peak at T ≃ 20~K. J2 component is suppressed by field as J2∝ B-0.54 and decays with temperature following to the power law J2∝(1 - T/Tdp )α where Tdp is the depinning temperature. Detailed comparison of the experimental data with pinning theories is presented.