Friedel-like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38

الأصل · EN

Using polarized and unpolarized neutron scattering we show that interstitial Fe in superconducting Fe₁₊yTe₁₋ₓSeₓ induces a magnetic Friedel-like oscillation that diffracts at Q(in-plane)=(1/2,0) and involves >50 neighboring Fe sites. The interstitial >2 muB moment is surrounded by compensating ferromagnetic four spin clusters that may seed double stripe ordering in Fe₁₊yTe. A semi-metallic 5-band model with (1/2,1/2) Fermi surface nesting and four fold symmetric super-exchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.