Modified magnetism within the coherence volume of superconducting FeSeTe

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Physical Review B

OSTI ID:1156754

Leiner, Jonathan C ^[1]; Thampy, Vivek ^[1]; Christianson, Andrew D ^[1]; Abernathy, D. ^[2]; Stone, Matthew B ^[1]; Lumsden, Mark D ^[1]; Sales, Brian C ^[1]; Safa-Sefat, Athena ^[1]; Hu, Jin ^[3]; Mao, Zhiqiang ^[3]; Bao, Wei ^[4]; Broholm, Collin L ^[1]

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1. ORNL
2. Oak Ridge National Laboratory (ORNL)
3. Tulane University
4. Renmin University of China

Neutron Scattering is used to probe magnetic interactions as superconductivity develops in opti- mally doped Fe_(1+ )Se_xTe_(1 x). Applying the first moment sum-rule to comprehensive neutron scatter- ing data, we extract the change in magnetic exchange energy [J_(R-R ) S_R S_R ] in the superconducting state referenced to the normal state. Oscillatory changes are observed for Fe-Fe displacements | R| < , where = 1.3(1) nm is the superconducting coherence length. Dominated by a large reduction in the second nearest neighbor exchange energy (-1.2(2) meV/Fe), the overall reduction in magnetic interaction energy is Hmag = 0.31(9) meV/Fe. Comparison to the superconducting condensation energy E_sc = 0.013(1) meV/Fe, which we extract from specific heat data, suggests the modified magnetism we probe drives superconductivity in Fe_(1+ )Se_xTe_(1 x)

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1156754
• Journal Information: Physical Review B, Vol. 90
• Country of Publication: United States
• Language: English