Abstract
The existence of large instantaneous local magnetic moments in paramagnetic phases is a direct signature of Mott localization. In order to track the doping evolution of fluctuating local moments in iron-based superconductors, we jointly use two fast probes, x-ray emission and absorption spectroscopies. Exploring K- and Cr-hole-doped , we find a systematic increase in the local moment with hole-doping, in contrast with inelastic neutron scattering measurements, which suggest an opposite trend. Our results support the theoretical scenario in which a Mott insulating state that would be realized for half-filled conduction bands has an influence throughout the phase diagram of these iron pnictides.
- Received 28 July 2016
DOI:https://doi.org/10.1103/PhysRevB.96.045133
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