Identifying the octupole Antiferromagnetic domain orientation in Mn${}_3$NiN by scanning Anomalous Nernst Effect microscopy

Abstract

The intrinsic anomalous Nernst effect in a magnetic material is governed by the Berry curvature at the Fermi energy and can be realized in non-collinear antiferromagnets with vanishing magnetization. Thin films of (001)-oriented Mn${}_3$NiN have their chiral antiferromagnetic structure located in the (111) plane facilitating the anomalous Nernst effect unusually in two orthogonal in-plane directions. The sign of each component of the anomalous Nernst effect is determined by the local antiferromagnetic domain state. In this work, a temperature gradient is induced in a 50 nm thick Mn${}_3$NiN two micron-size Hall cross by a focused scanning laser beam, and the spatial distribution of the anomalous Nernst voltage is used to image and identify the octupole macrodomain arrangement. Although the focused laser beam width may span many individual domains, cooling from room temperature through the antiferromagnetic transition temperature in an in-plane magnetic field prepares the domain state producing a checkerboard pattern resulting from the convolution of contributions from each domain. These images together with atomistic and micromagnetic simulations suggest an average macrodomain of the order of $1\mu m^2$.

25 pages 4 figures, 6 supplementary figures F.J. and J.K. both contributed equally to this manuscript. The following article has been accepted by Applied Physics Letters. After it is published, it will be found at https://aip.scitation.org/journal/apl

References in corpus (12)

• Berry phase effect in anomalous thermoelectric transport
• Universal Scaling Behavior of Anomalous Hall Effect and Anomalous Nernst Effect in Itinerant Ferromagnets
• Real-space imaging of non-collinear antiferromagnetic order with a single spin magnetometer
• Mott Relation for Anomalous Hall and Nernst effects in Ga1-xMnxAs Ferromagnetic Semiconductors
• Controlling spin current polarization through non-collinear antiferromagnetism
• Imaging current-induced switching of antiferromagnetic domains in CuMnAs
• Transverse thermoelectric generation using magnetic materials
• Giant magnetic anisotropy of the bulk antiferromagnets IrMn and IrMn3
• Spintronics on Chiral Objects
• Magneto-Seebeck microscopy of domain switching in collinear antiferromagnet CuMnAs
• Anomalous Hall and Nernst effects in ferrimagnetic Mn${}_4$N films: possible interpretation and prospect for enhancement
• Origin of negative anomalous Nernst thermopower in Mn-Ga ordered alloys

Cited by in corpus (8)

• Spin-Polarized Antiferromagnetic Spintronics
• Observation of the anomalous Nernst effect in altermagnetic candidate Mn5Si3
• Observation of cluster magnetic octupole domains in the antiferromagnetic Weyl semimetal Mn3Sn nanowire
• Anomalous Nernst effect in Mn${}_3$NiN thin films
• Room temperature weak collinear ferrimagnet with symmetry driven, large intrinsic magneto-optic signatures
• Higher-order Hall response arises from octupole order and scalar spin chirality in a noncollinear antiferromagnet
• Anomalous Nernst effect in Co thin films under laser irradiation
• Direct imaging and control of Berry curvature in noncollinear antiferromagnetic single-crystal thin films