TY - JOUR
T1 - Preparation of new superconductors by metal doping of two-dimensional layered materials using ethylenediamine
AU - Miao, Xiao
AU - Terao, Takahiro
AU - Yang, Xiaofan
AU - Nishiyama, Saki
AU - Miyazaki, Takafumi
AU - Goto, Hidenori
AU - Iwasa, Yoshihiro
AU - Kubozono, Yoshihiro
N1 - Funding Information:
The authors especially thank Prof. Hideki Okamoto of Okayama University for his valuable suggestion about the EDA molecule. This paper was partly supported by Grants-in-Aid No. 26105004 and No. 26400361 from Ministry of Education, Culture, Sports, Science, and Technology (MEXT). This paper was also supported by JST ACT-C Grant No. JPMJCR12YW, Japan, and by the Program for Promoting the Enhancement of Research Universities.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/7/5
Y1 - 2017/7/5
N2 - We have studied new superconductors prepared by metal doping of two-dimensional (2D) layered materials, FeSe and FeSe0.5Te0.5, using ethylenediamine (EDA). The superconducting transition temperatures (Tcs) of metal-doped FeSe and metal-doped FeSe0.5Te0.5, i.e., (EDA)yMxFeSe and (EDA)yMxFeSe0.5Te0.5 (M: Li, Na, and K), were 31-45 K and 19-25 K, respectively. The stoichiometry of each sample was clarified by energy dispersive x-ray (EDX) spectroscopy, and the x-ray powder diffraction pattern indicated a large expansion of lattice constant c, indicating the cointercalation of metal atoms and EDA. The pressure dependence of superconductivity in (EDA)yNaxFeSe0.5Te0.5 has been investigated at a pressure of 0-0.8GPa, showing negative pressure dependence in the same manner as (NH3)yNaxFeSe0.5Te0.5. The Tc-c phase diagrams of MxFeSe and MxFeSe0.5Te0.5 were drawn afresh from the Tc and c of (EDA)yMxFeSe and (EDA)yMxFeSe0.5Te0.5, showing that the Tc increases with increasing c but that extreme expansion of c reverses the Tc trend.
AB - We have studied new superconductors prepared by metal doping of two-dimensional (2D) layered materials, FeSe and FeSe0.5Te0.5, using ethylenediamine (EDA). The superconducting transition temperatures (Tcs) of metal-doped FeSe and metal-doped FeSe0.5Te0.5, i.e., (EDA)yMxFeSe and (EDA)yMxFeSe0.5Te0.5 (M: Li, Na, and K), were 31-45 K and 19-25 K, respectively. The stoichiometry of each sample was clarified by energy dispersive x-ray (EDX) spectroscopy, and the x-ray powder diffraction pattern indicated a large expansion of lattice constant c, indicating the cointercalation of metal atoms and EDA. The pressure dependence of superconductivity in (EDA)yNaxFeSe0.5Te0.5 has been investigated at a pressure of 0-0.8GPa, showing negative pressure dependence in the same manner as (NH3)yNaxFeSe0.5Te0.5. The Tc-c phase diagrams of MxFeSe and MxFeSe0.5Te0.5 were drawn afresh from the Tc and c of (EDA)yMxFeSe and (EDA)yMxFeSe0.5Te0.5, showing that the Tc increases with increasing c but that extreme expansion of c reverses the Tc trend.
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U2 - 10.1103/PhysRevB.96.014502
DO - 10.1103/PhysRevB.96.014502
M3 - Article
AN - SCOPUS:85026411072
SN - 2469-9950
VL - 96
JO - Physical Review B
JF - Physical Review B
IS - 1
M1 - 014502
ER -