Enhancement of critical current density in the force-free sate of BaHfO3-doped multilayered SmBa2Cu3Oy film

We report Jc enhancement of a multilayered SmBa2Cu3Oy film with BaHfO3 (BHO) nanoparticles owing to the so-called longitudinal magnetic fields effect. The maximum value of the Jc was 3.28 MA/cm2 under 0.25 T at 77 K. It was 10% larger than the Jc under the self-field (2.95 MA/cm2) of the film. We concluded that the reason for the Jc enhancement was the BHO nanoparticles acting as the flux pinning centers for the rotational flux motion driven by the force-free torque.