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Friedel-like oscillations from interstitial iron in superconducting Fe(1+y)Te0.62Se0.38
V Thampy1, J Kang, J A Rodriguez-Rivera
1Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Physical Review Letters
|April 3, 2012
Summary
Interstitial iron in superconducting iron telluride selenide creates magnetic oscillations. These oscillations, detected via neutron scattering, involve over 50 iron sites and may explain magnetic ordering in related materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- Superconducting iron chalcogenides (Fe(1+y)Te(1-x)Se(x)) exhibit complex magnetic properties.
- The role of interstitial atoms, particularly iron, in these properties remains an active area of research.
Purpose of the Study:
- To investigate the magnetic interactions induced by interstitial iron in superconducting Fe(1+y)Te(1-x)Se(x).
- To elucidate the relationship between interstitial magnetism and the emergence of magnetic ordering in related iron-based superconductors.
Main Methods:
- Utilized polarized and unpolarized neutron scattering techniques.
- Developed and applied a semimetallic five-band model incorporating Fermi surface nesting and superexchange interactions.
Main Results:
- Observed magnetic Friedel-like oscillations originating from interstitial Fe, diffracting at Q⊥=(1/2 0).
- Identified a significant interstitial magnetic moment (>2μB) surrounded by ferromagnetic four-spin clusters.
- The proposed model successfully explains the observed diffraction patterns.
Conclusions:
- Interstitial iron is a key player in inducing magnetic phenomena in Fe(1+y)Te(1-x)Se(x).
- The observed magnetic oscillations and clusters provide insights into the seeding of double stripe ordering in Fe(1+y)Te.
- The findings highlight the importance of interstitial magnetism in understanding iron-based superconductors.
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