Journal or Book Title
Physical Review Letters
The spin fluctuation spectra from nonsuperconducting Cu-substituted, and superconducting Co-substituted, BaFe2As2 are compared quantitatively by inelastic neutron scattering measurements and are found to be indistinguishable. Whereas diffraction studies show the appearance of incommensurate spin-density wave order in Co and Ni substituted samples, the magnetic phase diagram for Cu substitution does not display incommensurate order, demonstrating that simple electron counting based on rigid-band concepts is invalid. These results, supported by theoretical calculations, suggest that substitutional impurity effects in the Fe plane play a significant role in controlling magnetism and the appearance of superconductivity, with Cu distinguished by enhanced impurity scattering and split-band behavior.
American Physical Society
Kim, Min Gyu; Lamsal, Jagat; Heitmann, T. W.; Tucker, Gregory S.; Pratt, Daniel K.; Khan, Suffian N.; Lee, Y. B.; Alam, Aftab; Thaler, Alexander N.; Ni, Ni; Ran, Sheng; Bud'ko, Sergey L.; Marty, K. J.; Lumsden, M. D.; Canfield, Paul C.; Harmon, Bruce N.; Johnson, Duane D.; Kreyssig, Andreas; McQueeney, Robert J.; and Goldman, Alan I., "Effects of Transition Metal Substitutions on the Incommensurability and Spin Fluctuations in BaFe2As2 by Elastic and Inelastic Neutron Scattering" (2012). Ames Laboratory Publications. 288.