Comparative study of topological Hall effect and skyrmions in NiMnIn and NiMnGa

Authors

Wenyong Zhang, University of Nebraska-LincolnFollow
Balamurugan Balasubramanian, University of Nebraska-LincolnFollow
Ahsan Ullah, University of Nebraska - LincolnFollow
Rabindra Pahari, University of Nebraska - LincolnFollow
Xingzhong Li, University of Nebraska-LincolnFollow
Lanping Yue, University of Nebraska - LincolnFollow
Shah R. Valloppilly, University of Nebraska - LincolnFollow
Andrei Sokolov, University of Nebraska-LincolnFollow
Ralph Skomski, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska - LincolnFollow

ORCID IDs

Balamurugan Balasubramanian

Rabindra Pahari

Lanping Yue

Date of this Version

2019

Citation

Appl. Phys. Lett. 115, 172404 (2019)

Comments

https://doi.org/10.1063/1.5120406

Abstract

A nonequilibrium rapid-quenching method has been used to fabricate NiMnIn and NiMnGa alloys that are chemically and morphologically similar but crystallographically and physically very different. NiMnGa crystallizes in a Ni2In-type hexagonal structure, whereas NiMnIn is a cubic Heusler alloy. Both alloys yield a topological Hall effect contribution corresponding to bubble-type skyrmion spin structures, but it occurs in much lower magnetic fields in NiMnIn as compared to NiMnGa. The effect is unrelated to net Dzyaloshinskii-Moriya interactions, which are absent in both alloys due to their inversion-symmetric crystal structures. Based on magnetic-force microscopy, we explain the difference between the two alloys by magnetocrystalline anisotropy and uniaxial and cubic anisotropies yielding full-fledged and reduced topological Hall effects, respectively. Since NiMnIn involves small magnetic fields (0.02–0.3 kOe) at and above room temperature, it is of potential interest in spin electronics.