Publication

Journal	Scientific Reports
Publisher	Scientific Reports (Nature.com)
Title of proceedings	Scientific Reports

The exchange interactions in heavy-fermion materials can trigger complex magnetic ground states that arise from localized or itinerant electrons. It is an open question how magnetic order is affected when the Fermi surface topology is altered upon hybridization of local electronic f-states with the conduction band. Here we study the evolution of magnetic order in the series Nd1 xCexCoIn5 that features a Kondo breakdown within an antiferromagnetic phase. We find two distinct magnetic structures separated by a transition that is detached from the emergence of heavy-bands. This provides evidence for a novel heavy fermion ground state, in which magnetism and the Kondo coupling can be tuned separately.The results suggest that magnetic order originates from remnant unscreened moments with microscopic exchange parameters that are modified by chemical substitution.