Hund metals are multiorbital systems with $3d$ or $4d$ electrons exhibiting both an itinerant character and local moments, and they feature Kondo-like screenings of local orbital and spin moments, with suppressed coherence temperatures driven by Hund's coupling $J_H$. They often exhibit magnetic order at low temperature, but how the interaction between the Kondo-like screening and long-range magnetic order is manifested in the quasiparticle spectrum remains an open question. Here, we present the spectroscopic signature of such an interaction in a Hund metal candidate MnSi exhibiting weak ferromagnetism. Our photoemission measurements reveal renormalized quasiparticle bands near the Fermi level with strong momentum dependence: The ferromagnetism manifests through possibly exchange-split bands (Q1) below $T_C$, while the spin/orbital screenings lead to the gradual development of quasiparticles (Q2) upon cooling. Our results demonstrate how the characteristic spin/orbital coherence in a Hund metal could coexist and compete with the magnetic order to form a weak itinerant ferromagnet, via quasiparticle bands that are well separated in momentum space and exhibit distinct temperature dependence. Our results imply that the competition between the spin/orbital screening and the magnetic order in a Hund metal bears interesting similarities to the Kondo lattice systems.

• Received 20 June 2022
• Revised 26 September 2022
• Accepted 12 October 2022

DOI:https://doi.org/10.1103/PhysRevB.106.L161112