TY - JOUR
T1 - Appearance of superconductivity at the vacancy order-disorder boundary in KxFe2-ySe2
AU - Duan, Chunruo
AU - Yang, Junjie
AU - Ren, Yang
AU - Thomas, Sean M.
AU - Louca, Despina
N1 - Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].
PY - 2018/5/14
Y1 - 2018/5/14
N2 - The role of phase separation and the effect of Fe-vacancy ordering in the emergence of superconductivity in alkali metal doped iron selenides AxFe2-ySe2 (A = K, Rb, Cs) is explored. High energy x-ray diffraction and Monte Carlo simulation were used to investigate the crystal structure of quenched superconducting (SC) and as-grown nonsuperconducting (NSC) KxFe2-ySe2 single crystals. The coexistence of superlattice structures with the in-plane 2×2 K-vacancy ordering and the 5×5 Fe-vacancy ordering were observed in both the SC and NSC crystals alongside the I4/mmm Fe-vacancy-free phase. Moreover, in the SC crystals, an Fe-vacancy-disordered phase is additionally proposed to be present. Monte Carlo simulations suggest that it appears at the boundary between the I4/mmm vacancy-free phase and the I4/m vacancy-ordered phases (5×5). The vacancy-disordered phase is nonmagnetic and is most likely the host of superconductivity.
AB - The role of phase separation and the effect of Fe-vacancy ordering in the emergence of superconductivity in alkali metal doped iron selenides AxFe2-ySe2 (A = K, Rb, Cs) is explored. High energy x-ray diffraction and Monte Carlo simulation were used to investigate the crystal structure of quenched superconducting (SC) and as-grown nonsuperconducting (NSC) KxFe2-ySe2 single crystals. The coexistence of superlattice structures with the in-plane 2×2 K-vacancy ordering and the 5×5 Fe-vacancy ordering were observed in both the SC and NSC crystals alongside the I4/mmm Fe-vacancy-free phase. Moreover, in the SC crystals, an Fe-vacancy-disordered phase is additionally proposed to be present. Monte Carlo simulations suggest that it appears at the boundary between the I4/mmm vacancy-free phase and the I4/m vacancy-ordered phases (5×5). The vacancy-disordered phase is nonmagnetic and is most likely the host of superconductivity.
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U2 - 10.1103/PhysRevB.97.184502
DO - 10.1103/PhysRevB.97.184502
M3 - RGC 21 - Publication in refereed journal
SN - 2469-9950
VL - 97
JO - Physical Review B
JF - Physical Review B
IS - 18
M1 - 184502
ER -