Magnetic impurities in the pnictide superconductor Ba_1−xK_xFe₂As₂

As75NMR of Ba(Fe0.93CoOh1, Mounce2, Mukhopadhyay3 et al. 2011Phys. Rev. BSelf Cite239251View full textAdd to dashboardCite

“…Both the orbital, K orb , and the quadrupolar shift, K q , are expected to be temperature independent. Additional magnetic shifts which we call K para could be associated with impurities, 40 and in principle, could be temperature dependent, although this is not seen in cuprates, 41,42 nor do we find any evidence for this in the present work.…”

As vacancies, local moments, and Pauli limiting in LaFeAs1−δO0.9F0.1superconductors

“…However, at variance with our findings also a 20% T c -suppression and a broadening of the NMR spectra has been observed pointing to sizable disorder. The peculiar magnetism has been ascribed by the authors to large local moments from a small amount of incorporated Sn occupying Assites 37,38 . This way being seemingly responsible for a significant paramagnetic pair-breaking and the observed T csuppression.…”

Interplane resistivity of underdoped single crystals (Ba1−xKx)Fe2AsTanatar1, Straszheim2, Kim3 et al. 2014Phys. Rev. B

“…Sn-grown parent Ba122 shows quite significant suppression of T SM down to 90 K [38], compared to approximately 135 K [7] in FeAs flux crystals or polycrystalline materials [1,4]. This strong suppression is ascribed to incorporation of Sn at sub-percent level [39]. That is why the goal of this study is to characterize the doping evolution of the temperature-dependent resistivity in high-quality single crystals of BaK122 grown from FeAs flux.…”