4 research outputs found
Low-temperature Synthesis of FeTe0.5Se0.5 Polycrystals with a High Transport Critical Current Density
We have prepared high-quality polycrystalline FeTe0.5Se0.5 at temperature as
low as 550{\deg}C. The transport critical current density evaluated by the
current-voltage characteristics is over 700 A/cm2 at 4.2 K under zero field,
which is several times larger than FeTe0.5Se0.5 superconducting wires. The
critical current density estimated from magneto-optical images of flux
penetration is also similar to this value. The upper critical field of the
polycrystalline FeTe0.5Se0.5 at T = 0 K estimated by
Werthamer-Helfand-Hohenberg theory is 585 kOe, which is comparable to that of
single crystals. This study gives some insight into how to improve the
performance of FeTe0.5Se0.5 superconducting wires.Comment: 12 pages, 6 figure
Superconducting properties of FeSe wires and tapes prepared by gas diffusion technique
Superconducting FeSe in the form of wires and tapes were successfully
fabricated using a novel gas diffusion procedure. Structural analysis by mean
of x-ray diffraction shows that themain phase of tetragonal PbO-type FeSe was
obtained by this synthesis method. The zero resistivity transition temperature
of the FeSe was confirmed to be 9.3 K. The critical current density as high as
137 A/cm^2 (4 K, self field) has been observed. The results suggest that the
diffusion procedure is promising in preparing high-quality FeSe wires and
tapes.Comment: 13 pages, 6 figures, Supercond. Sci. Technol. accepte