Investigation of the Longitudinal Magnetic Field Effect on Multilayered- $\text{SmBa}_{2}\text{Cu}_{3}\text{O}_{y}$ Films Fabricated on Single-Crystal and Metal Substrates

We discuss the longitudinal magnetic field (LMF) effect in BaHfO
₃
(BHO)-doped multilayered (ML) SmBa
₂
Cu
₃
Oy (SmBCO) films. We observed critical current density (J
_c
) enhancement in the form of a J
_c
peak with increasing magnetic fields due to the LMF effect at various measurement temperatures on an ML-SmBCO film fabricated on a single-crystalline substrate. These J
_c
peaks were higher than J
_c
s under self-field, and the J
_c
gain was temperature dependent. We concluded that the J
_c
gain was related to the BHO nanorod diameter and the diameter of flux lines along the ab-plane. We also attempted to determine the J
_c
gain of SmBCO films with a similar film structure that were fabricated on IBAD-MgO-buffered metal substrates.