Determination of the critical current density and the flux pinning force in single crystals YBa2Cu3O7-δ from the magnetization hysteresis cycles

• Published in: Chinese journal of physics (Taipei) 2021-08, Vol.72, p.628-635
• Main Authors: Abou El Hassan, Ahmed, Labrag, Abdelaziz, Bghour, Mustapha, Taoufik, Ahmed
• Format: Article
• Language: English
• Subjects: Critical currents; Critical field; Hysteresis; Magnetization; Pinning forces
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2020.06.025

•The magnetization hysteresis loops of YBa2Cu3O7-δ single crystals are presented.•Single crystals YBa2Cu3O7-δ have shown high critical current density.•The Dew-Hughes model was used to analyze the pinning mechanism in YBa2Cu3O7-δ.•Under high temperatures, point pinning is more dominant than surface pinning. In this study, the magnetization measurements have been performed on high-temperature superconductor's single crystals YBa2Cu3O7-δ at large ranges of temperature T (15-85 K) and in magnetic fields up to 6T at different values of the angle θ between the applied magnetic field and c-axis. The critical current density Jc deduced from the magnetic hysteresis loops by the Bean formula for H parallel to the c-axis (θ=0°), our results have shown that the critical current density Jc was strongly dependent on the applied magnetic field. The pinning force Fp=Jc×μ0H was determined from magnetization for H//c, however, a plot of the normalized pinning force density fp= Fp/Fpmax as a function of the reduced magnetic field h= H/Hirr at different temperatures have shown good scaling with the form fp ~hp(1-h)q, where p and q are scaling parameters. We also found that the point pinning is more dominant than surface pinning under high temperatures.