Enhancement of critical current densities by the longitudinal magnetic field effect in multilayered SmBa2Cu3Oy films controlling the film thickness

Abstract

We report on the film thickness and the interface density dependence of critical current density (Jc) in multilayered SmBa2Cu3Oy (SmBCO) films with short BaHfO3 (BHO) nanorods under the force-free state. In the investigation into the film thickness dependence of Jc, we fixed the layer thickness and changed the total film thickness. However, in the investigation into the interface density dependence of Jc, we fixed the total film thickness and changed each layer’s thickness. We observed the Jc peaks via the longitudinal magnetic field effect on multilayered films which have a certain film thickness of over 400 nm and a certain interface density of over 80 layers/μm. We considered that two types of flux pinning were needed for the Jc enhancement and these were against the force-free torque in the ab plane and the Lorentz force along the c-axis.