NEUTRON SCATTERING OF NEW IRON-BASED SUPERCONDUCTORS
Efrain E. Rodriguez,1 Chris Stock,1 Nick P. Butch,3 Johnpierre Paglione,3 Mark A. Green1,3
Superconductivity and magnetism are often incompatible bulk properties in materials. Therefore, when in 2008 Kamihara and co-workers discovered that iron-based compounds could become superconducting, the field received another surge in activity similar to that of the high-Tc cuprate superconductors. We present here how neutron diffraction is vital towards understanding key parameters of these new materials such as chemical composition, crystal structure, and magnetic ordering. The neutron data presented are on the Fe(Te,Se,S) family of compounds and includes single crystal, powder, unpolarized and polarized measurements. In addition, we present inelastic neutron scattering data from the new Multi-Analyzer Crystal Spectrometer, which helps us map out magnetic excitations in reciprocal space and therefore obtain the energy transfer versus q-space dispersion relations. Thus, with neutron diffraction and spectroscopy combined, we detail both the structural and dynamical behavior of this new important class of materials.
 Y. Kamihara, T. Watanabe, M. Hirano, and H. Hosono, J. Am. Chem. Soc., 130, 3296 (2008).