Using polarized and unpolarized neutron scattering, we show that interstitial Fe in superconducting Fe 1+yTe 1-xSe x induces a magnetic Friedel-like oscillation that diffracts at Q=(120) and involves >50 neighboring Fe sites. The interstitial >2μ B moment is surrounded by compensating ferromagnetic four-spin clusters that may seed double stripe ordering in Fe 1+yTe. A semimetallic five-band model with (1212) Fermi surface nesting and fourfold symmetric superexchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)