Strongly enhanced flux pinning in one-step deposition of BaFe₂(As₀.₆₆P₀.₃₃)₂ superconductor films with uniformly dispersed BaZrO₃ nanoparticles.
The high upper critical field and low anisotropy of the iron-based superconductor BaFe₂As₂ make it promising for its use in the construction of superconducting magnets. However, its critical current density in high magnetic fields needs to be improved. Here we demonstrate a simple, one-step and industrially scalable means of achieving just this. We show that introducing controlled amounts of uniformly dispersed BaZrO₃ nanoparticles into carrier-doped BaFe₂As₂ significantly improves its superconducting performance without degrading its structural or superconducting properties. Our BaFe₂(As₀.₆₆P₀.₃₃)₂ films also exhibit an increase in both the irreversibility line and critical current density at all magnetic-field orientations. These films exhibit nearly isotropic critical current densities in excess of 1.5 MA cm⁻² at 15 K and 1 T--seven times higher than previously reported for BaFe₂As₂ films. The vortex-pinning force in these films reaches ~59 GN m⁻³ at 5 K and 3-9 T, substantially higher than that of the conventional Nb₃Sn wire.
1] Superconductivity Research Laboratory, International Superconductivity Technology Center, 10-13, Shinonome 1-chome, Koto-ku, Tokyo 135-0062, Japan [2] Graduate School of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino-shi, Tokyo 180-8633, Japan.
Masashi
M
Miura
Boris
B
Maiorov
Takeharu
T
Kato
Takashi
T
Shimode
Keisuke
K
Wada
Seiji
S
Adachi
Keiichi
K
Tanabe