Abstract
We have performed resistivity and inelastic neutron scattering measurements on three samples of FeCuTeSe with , 0.02, and 0.1. It is found that with increasing Cu doping the sample's resistivity deviates progressively from that of a metal. However, in contrast to expectations that replacing Fe with Cu would suppress the magnetic correlations, the low-energy ( meV) magnetic scattering is enhanced in strength, with greater spectral weight and longer dynamical spin-spin correlation lengths. Such enhancements can be a consequence of either enlarged local moments or a slowing down of the spin fluctuations. In either case, the localization of the conduction states induced by the Cu doping should play a critical role. Our results are not applicable to models that treat 3 transition metal dopants simply as effective electron donors.
- Received 25 July 2013
DOI:https://doi.org/10.1103/PhysRevB.88.144509
©2013 American Physical Society