（Superconductivity at 31K in the “111”-type iron arsenide superconductor Na1-xFeAs induced by pressure)
S. J. Zhang, X. C. Wang, Q. Q. Liu, Y. X. Lv, X. H. Yu, Z. J. Lin, Y. S. Zhao, L. Wang, Y. Ding, H. K. Mao and C. Q. Jin
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 (Tc) increases from 26K to a maximum of 31K as the pressure increases from ambient pressure to 3GPa. 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.