We report resistivity measurements performed on KFe 2As 2 single crystals down to T = 0:3K and in magnetic fields up to 17.5 T. The in-plane resistivity vs T curve has a convex shape down to ∼50K and shows a T 2 dependence below ∼45 K. The ratio of the c-axis to in-plane resistivities is ∼10 at room temperature and ∼40 at 4.2 K. The superconducting upper critical field B ab c2(T) has been determined from the resistivity data: B ab c2(0) = 4:47T and B c c2(0) = 1:25 T. The anisotropy parameter T = B ab c2/B c c2 increases with T and is 6.8 at T = Tc. The strong curvature of the B ab c2(T) curve indicates the existence of strong spin paramagnetic effects.
|Journal||journal of the physical society of japan|
|Publication status||Published - 2009 Jun|
- Iron pnictide superconductor
- Upper critical field
ASJC Scopus subject areas
- Physics and Astronomy(all)