Disappearance of Static Magnetic Order and Evolution of Spin Fluctuations in Fe1+ SexTe1−x
We report neutron-scattering studies on static magnetic orders and spin excitations in the Fe-based chalcogenide system Fe{sub 1+{delta}}Se{sub x}Te{sub 1-x} with different Fe and Se compositions. Short-range static magnetic order with an in-plane wave vector near the (0.5,0) (using the two-Fe unit cell), together with strong low-energy magnetic excitations is found in all nonsuperconducting samples for Se doping up to 45%. When the static order disappears and bulk superconductivity emerges, the spectral weight of the magnetic excitations shifts to the region of reciprocal space near the in-plane wave vector (0.5, 0.5), corresponding to 'collinear' spin correlations. Our results suggest that there is a strong correlation between superconductivity and the character of the magnetic order/fluctuations in this system. Excess Fe appears to be important for stabilizing the magnetic order that competes with superconductivity.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- DOE - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1000446
- Report Number(s):
- BNL-94355-2010-JA; ISSN 1550-235X; R&D Project: po-010; KC0202010; TRN: US1100122
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 10; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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