Superconductivity at 31 K in the "111"-type iron arsenide superconductor Na<sub>1-x</sub>FeAs induced by pressure

Zhang, S. J.; Wang, X. C.; Liu, Q. Q.; Lv, Y. X.; Yu, X. H.; Lin, Z. J.; Zhao, Y. S.; Wang, L.; Ding, Y.; Mao, H. K.; Jin, C. Q.
2009
EPL
DOI
10.1209/0295-5075/88/47008
The effect of pressure on the superconductivity of "111"-type Na1-xFeAs is investigated through temperature-dependent electrical-resistance measurements in a diamond anvil cell. The superconducting transition temperature (T-c) increases from 26 K to a maximum of 31 K as the pressure increases from ambient pressure to 3 GPa. Further increasing pressure suppresses T-c drastically. The behavior of pressure-tuned T-c in Na1-xFeAs is much different from that in LixFeAs, although they have the same Cu2Sb-type structure. Copyright (C) EPLA, 2009