Identify the magnetic phase responsible for anomalous transport in thin films

Identify whether the anomalous transport observed above 200 K in thin Mn$_5$Si$_3$ films arises from a distinct magnetic phase or from substantial deviations from homogeneous stoichiometric bulklike Mn$_5$Si$_3$, such as altered site occupation, off-stoichiometry, or surface reconstruction.

Background

The anomalous Hall and Nernst effects reported in thin films persist to temperatures substantially above the bulk AFM2 transition, whereas structural, resistive, and magnetoresistive anomalies indicate a magnetic transition near the bulk energy scale. The calculations in the paper disfavor stabilization of the proposed zone-center altermagnetic phase by moderate epitaxial strain in a bulklike structure.

The authors therefore explicitly retain alternative explanations involving a different magnetic phase or chemically and structurally modified films. Existing experimental data do not distinguish among these possibilities, leaving the origin of the high-temperature Hall-active state unresolved.