Flux Pinning Properties at Low Temperatures in $ \hbox{BaHfO}_{3}$ Doped $\hbox{SmBa}_{2}\hbox{Cu}_{3} \hbox{O}_{y}$ Films

BaHfO
₃
(BHO) is attracting attention as a new material forming nanorod as well as BaMO
₃
(BMO: M = Zr, Sn), and it was reported that the flux pinning force of BHO nanorod is effective even at low temperatures. It is essential to understand the flux pinning properties of an APC-doped REBCO film at low temperatures in order to achieve the high-performance superconducting applications. We fabricated 8.4 mol. % BHO-doped SmBa
₂
Cu
₃
O
_y
(SmBCO) film on LaAlO
₃
(LAO) substrates by pulsed laser deposition method and measured the superconducting properties at 77, 65, 40, and 20 K. As for the magnetic field dependence of
J
_c
, the
J
_c
of the BHO-doped SmBCO film was significantly higher than that of the pure SmBCO film at all temperatures. Furthermore, in the magnetic field angular dependence of
J
_c
, the BHO-doped SmBCO film exhibited the peaks of
J
_c
around
B
//
c
at 77, 65, and 40 K in 3 T. These results suggested that the flux pinning force of BHO nanorod was effective even at 65 and 40 K.