Pressure effects on the electron-doped highTcsuperconductor BaFe2−xCoxAs2

K Ahilan, J Balasubramaniam, F L Ning, T Imai, A S Sefat, R Jin, M A McGuire, B C Sales, D Mandrus
2008 Journal of Physics: Condensed Matter  
Application of pressures or electron-doping through Co substitution into Fe sites transforms the itinerant antiferromagnet BaFe(2)As(2) into a superconductor with the Tc exceeding 20K. We carried out systematic transport measurements of BaFe(2-x)Co(x)As(2) superconductors in pressures up to 2.5GPa, and elucidate the interplay between the effects of electron-doping and pressures. For the underdoped sample with nominal composition x = 0.08, application of pressure strongly suppresses a magnetic
more » ... stability while enhancing Tc by nearly a factor of two from 11K to 21K. In contrast, the optimally doped x=0.20 sample shows very little enhancement of Tc=22K under applied pressure. Our results strongly suggest that the proximity to a magnetic instability is the key to the mechanism of superconductivity in iron-pnictides.
doi:10.1088/0953-8984/20/47/472201 fatcat:on5qxz2vbjhfdjk43k6ddzkpwq