Superconducting Properties in SmBa2Cu3Oy Films With High Density of BaHfO3 Nanorods Fabricated With a Seed Layer

A high density of BaMO
₃
(BMO) nanorods within a REBa
₂
Cu
₃
O
_y
(REBCO) film can be generated by heavy doping of the BMO. This is very effective in improving superconducting properties in high magnetic fields. However, heavy doping causes a significant T
_c
reduction. Introduction of a high density of BMO nanorods into REBCO films without reduction in T
_c
is required. To this end, we deposited SmBa
₂
Cu
₃
O
_y
(SmBCO) films with various amount of BaHfO
₃
(BHO) by a pulsed laser deposition (PLD) method using a seed-layer technique and a low-temperature growth (LTG) technique. Using this technique, we can fabricate a purely c-axis-oriented SmBCO film even at low substrate temperatures T
_s
. The SmBCO films with BHO were fabricated at low T
_s
of 750 °C without heavy doping of BHO. As a result, the BHO nanorods became thinner and denser than those within SmBCO films fabricated by conventional PLD methods at high T
_s
. The maximum density was 4780/μm
²
, and the B
_φ
of the film reached 9.9 T. These samples showed high T
_c
(> 90 K). We have therefore successfully fabricated high-T
_c
SmBCO films with high densities of BHO nanorods using the LTG technique.