Abstract
γ-FeMn is a topological antiferromagnet which hosts a noncoplanar spin structure at room temperature, promising for application to antiferromagnetic spintronics. In this work, we have investigated magnetotransport properties of FeMn thin films grown by dc magnetron sputtering on Al2O3 (0001) substrates. γ-phase (fcc) FeMn thin films are successfully obtained with use of a Cu seed layer covering with the Al2O3 surface, while nonmagnetic α-phase (bcc) FeMn thin films are formed without a Cu seed layer. When the sputtering temperature is set at 500 °C, γ-FeMn films grown on Cu/Al2O3 are highly oriented along the (111) plane, but minor α-Fe phases are included owing to alloying with the Cu layer. Ferromagnetic transports of α-Fe phases are observed in Hall and Nernst effects at low magnetic fields. By contrast, the slope of Hall conductivity at high magnetic fields is found to be several times larger for the γ-FeMn phase than for the α-FeMn phase, which suggests that the antiferromagnetic spin structure of γ-FeMn contributes to the Hall effect.
Highlights
Antiferromagnetic materials have attracted much attention in the spintronics field
Though normal Hall effects originate from the Lorentz force due to external magnetic fields, an emerging magnetic field originating from the Berry curvature generates additional Hall effects for electrons, known as intrinsic anomalous Hall effect (AHE)[9] and topological Hall effect (THE).[10,11,12]
This result is consistent with the fact that a substrate with fcc structure is necessary for the growth of the γ-FeMn phase.[24,25]
Summary
Antiferromagnetic materials have attracted much attention in the spintronics field. A large AHE due to a non-vanishing Berry curvature in antiferromagnets with a noncollinear spin arrangement was recently reported for Mn3Ir,[13] Mn3Sn,[14] and Mn3Ge.[4,15] In Mn3Sn and Mn3Ge, Weyl points in the momentum space may lead to the large AHE.[16,17] On the other hand, even in the absence of spin-orbit coupling, the noncoplanarity of neighboring spins replaces the spin-orbit coupling as the mechanism of the Hall effect
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
