TY - JOUR
T1 - Boosting Superconducting Properties of Fe(Se, Te) via Dual-Oscillation Phenomena Induced by Fluorine Doping
AU - Liu, Jixing
AU - Zhang, Shengnan
AU - Li, Meng
AU - Sang, Lina
AU - Li, Zhi
AU - Cheng, Zhenxiang
AU - Zhao, Weiyao
AU - Feng, Jianqing
AU - Li, Chengshan
AU - Zhang, Pingxiang
AU - Dou, Shixue
AU - Wang, Xiaolin
AU - Zhou, Lian
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/5/22
Y1 - 2019/5/22
N2 - Fluorine-doped Fe(Se, Te) has been successfully synthesized using the melting method. A dual-oscillation effect was found in the F-doped sample, which combined both microstructural oscillation and chemical compositional oscillation. The microstructural oscillation could be attributed to alternate growth of tetragonal β-Fe(Se, Te) and hexagonal δ-Fe(Se, Te), which formed a pearlite-like structure and led to the enhancement of δl flux pinning due to the alternating distributed nonsuperconducting δ-Fe(Se, Te) phase. The chemical compositional oscillations in β-Fe(Se, Te) phase were because of the inhomogeneously distributed Se and Te, which changes the pinning mechanism from surface pinning in the undoped sample to Δκ pinning in the 5% F-doped one. As a result, the critical current, upper critical field, and thermally activated flux-flow activation energy of FeSe0.45Te0.5F0.05 were enhanced by 7, 2, and 3 times, respectively. Our work revealed the physical insights into F-doping resulting in high-performance Fe(Se, Te) superconductors and inspired a new approach to optimize superconductivities in iron-based superconductors through phase and element manipulations.
AB - Fluorine-doped Fe(Se, Te) has been successfully synthesized using the melting method. A dual-oscillation effect was found in the F-doped sample, which combined both microstructural oscillation and chemical compositional oscillation. The microstructural oscillation could be attributed to alternate growth of tetragonal β-Fe(Se, Te) and hexagonal δ-Fe(Se, Te), which formed a pearlite-like structure and led to the enhancement of δl flux pinning due to the alternating distributed nonsuperconducting δ-Fe(Se, Te) phase. The chemical compositional oscillations in β-Fe(Se, Te) phase were because of the inhomogeneously distributed Se and Te, which changes the pinning mechanism from surface pinning in the undoped sample to Δκ pinning in the 5% F-doped one. As a result, the critical current, upper critical field, and thermally activated flux-flow activation energy of FeSe0.45Te0.5F0.05 were enhanced by 7, 2, and 3 times, respectively. Our work revealed the physical insights into F-doping resulting in high-performance Fe(Se, Te) superconductors and inspired a new approach to optimize superconductivities in iron-based superconductors through phase and element manipulations.
KW - Fe(Se, Te)
KW - chemical doping
KW - flux pinning
KW - interface effect
KW - iron-based superconductor
KW - melting process
UR - https://www.scopus.com/pages/publications/85065875060
U2 - 10.1021/acsami.9b02469
DO - 10.1021/acsami.9b02469
M3 - 文章
C2 - 31007006
AN - SCOPUS:85065875060
SN - 1944-8244
VL - 11
SP - 18825
EP - 18832
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 20
ER -