We conducted a small-angle neutron scattering experiments (SANS) on the ferromagnetic semi-metal EuB6, where we observed direct evidence for the presence of magnetic polarons. We carried out SANS experiments over a large range of scattering vectors ∣q∣ from 0.006 to 0.140~\AA−1 and 2 to 60~K. Just above TC our experiments show magnetic scattering intensity, which has a Lorentzian dependence on the wave vector, which is characteristic for the presence of magnetic polarons. Below TC the polarons merge and most of the observed intensity is due to scattering from domain walls.We were able to extract a correlation length ξ which ranges from 100 to 300~\AA\ for the size of the magnetic polarons. This size is much larger than one would expect for magnetic fluctuations, demonstrating the influence the magnetic polarons on the phase transition. We were able to extract a correlation length ξ which ranges from 100 to 300~\AA\ for the size of the magnetic polarons. This size is much larger than one would expect for magnetic fluctuations, demonstrating the influence the magnetic polarons on the phase transition.
@article{arxiv.2210.12210,
title = {Does a low-carrier density ferromagnet hold the key to understanding high temperature superconductors?},
author = {Gabrielle Beaudin and Alexandre Désilets-Benoit and Andrea Daniele Bianchi and Robert Arnold and Stavros Samothrakitis and Kilian D. Stenning and Mark Laver and Simon Gerber and Nikola Anna Galvan Leo and Jorge L. Gavilano and Michel Kenzelmann and Michael Nicklas},
journal= {arXiv preprint arXiv:2210.12210},
year = {2022}
}