Pressure-tuned superconductivity and normal-state behavior in Ba(Fe0.943Co0.057)2As2

Abstract

Bud'ko, Sergey L.; Canfield, Paul C.; Panagopoulos, C.; Li, P. G.; Mu, G.; Hu, T.; Almasan, C. C.; and Xiao, H., "Pressure-tuned superconductivity and normal-state behavior in Ba(Fe0.943Co0.057)2As2 near the antiferromagnetic boundary" (2018). Ames Laboratory Accepted Manuscripts. 172. https://lib.dr.iastate.edu/ameslab_manuscripts/172Pressure-tuned superconductivity and normal-state behavior in Ba(Fe0.943Co0.057)2As2 near the antiferromagnetic boundary AbstractSuperconductivity in iron pnictides is unconventional and pairing may be mediated by magnetic fluctuations in the Fe sublattice. Pressure is a clean method to explore superconductivity in iron based superconductors by tuning the ground state continuously without introducing disorder. Here we present a systematic high pressure transport study in Ba ( Fe 1 − x Co x ) 2 As 2 single crystals with x = 0.057, which is near the antiferromagnetic instability. Resistivity ρ = ρ 0 + A T n was studied under applied pressure up to 7.90 GPa. The parameter n approaches a minimum value of n ≈ 1 at a critical pressure P c = 3.65 GPa. Near P c , the superconducting transition temperature T c reaches a maximum value of 25.8 K. In addition, the superconducting diamagnetism at 2 K shows a sudden change around the same critical pressure. These results may be associated with a possible quantum critical point hidden inside the superconducting dome, near optimum T c . DisciplinesCondensed Matter Physics | Physics Superconductivity in iron pnictides is unconventional and pairing may be mediated by magnetic fluctuations in the Fe sublattice. Pressure is a clean method to explore superconductivity in iron based superconductors by tuning the ground state continuously without introducing disorder. Here we present a systematic high pressure transport study in Ba(Fe 1−x Co x ) 2 As 2 single crystals with x = 0.057, which is near the antiferromagnetic instability. Resistivity ρ = ρ 0 + AT n was studied under applied pressure up to 7.90 GPa. The parameter n approaches a minimum value of n ≈ 1 at a critical pressure P c = 3.65 GPa. Near P c , the superconducting transition temperature T c reaches a maximum value of 25.8 K. In addition, the superconducting diamagnetism at 2 K shows a sudden change around the same critical pressure. These results may be associated with a possible quantum critical point hidden inside the superconducting dome, near optimum T c .

Pressure tuning of iron-based superconductor Ca10(Pt3As8) ((Fe0.95Pt0.05)2As2)5

“…The superconducting transition temperature T c increases initially and then decreases with increasing pressure. The dome shape of T c with P is similar to that of 122 family of iron-based superconductor [28][29][30][31], but different from 1111 family, for example, CaFeAsF, where T c is monotonically suppressed with increasing pressure [16,32]. The resistivity maximum T peak , which is a result of competition between semiconductor behavior and superconducting fluctuations above T c , follows well the tendency of the pres sure dependence of T c .…”

The effect of critical coupling constants on superconductivity enhancement

“…In particular, for strong coupling superconductors, the pressure effect is positive and may lead to a dome-like delineation at higher pressure. These characteristics were observed in cuprate superconductors 12,44 , iron-based superconductors 13,14,45 , and hydrogen-rich superconductors 15,16 . In Table 2, the value of positive or dome-like pressure effect superconductors are listed.…”

Pressure effects on iron-based superconductor CaFe0.88Co0.12AsF

“…For example, the T c of FeSe is enhanced to about 37 K while the T c at ambient condition is 8 K [10]. Pressure can also induce superconductivity in the parent compound where superconductivity is absent [11][12][13], induce a second superconducting phase [14], and tune the system to a quantum critical point at zero temperature [15]. More importantly, pressure can provide a clean way to tune the ground state continuously without introducing disorders and dopants.…”