Unconventional magnetic properties of the weakly ferromagnetic metal BaIrO_3

TL;DR

This study reveals unconventional magnetic behavior in BaIrO_3, including small-moment magnetism and magnetic rearrangements at different transition temperatures, driven by Fermi surface changes and charge-density wave formation.

Contribution

It provides the first muon-spin relaxation evidence of small-moment magnetism and magnetic rearrangements in BaIrO_3, highlighting unconventional magnetic properties linked to electronic structure changes.

Findings

Small-moment magnetism below 183 K

Magnetic moment rearrangement at 26 K

Unconventional magnetic behavior linked to Fermi surface changes

Abstract

We present experimental evidence for small-moment magnetism below the ferromagnetic transition temperature (T_c3 = 183 K) in the quasi-one-dimensional metal BaIrO_3. Further, we identify rearrangement of the local magnetic moment distribution, which leaves the bulk magnetization unchanged, at the Mott-like transition (T_c1 = 26 K). These results are only possible via muon-spin relaxation ($\mu$SR) techniques, since neutron scattering studies are hindered by the large absorption of neutrons by Ir. The low temperature characteristics of this compound, as revealed by $\mu$SR, are unconventional, and suggest that its magnetic properties are driven by changes occuring at the Fermi surface due to the formation of a charge-density wave state.