Taylor, James M. and Lesne, Edouard and Markou, Anastasios and Dejene, Fasil Kidane and Sivakumar, Pranava Keerthi and Poellath, Simon and Rana, Kumari Gaurav and Kumar, Neeraj and Luo, Chen and Ryll, Hanjo and Radu, Florin and Kronast, Florian and Werner, Peter and Back, Christian H. and Felser, Claudia and Parkin, Stuart S. P. (2019) Magnetic and electrical transport signatures of uncompensated moments in epitaxial thin films of the noncollinear antiferromagnet Mn3Ir. APPLIED PHYSICS LETTERS, 115 (6): 062403. ISSN 0003-6951, 1077-3118
Full text not available from this repository. (Request a copy)Abstract
Noncollinear antiferromagnets, with either an L1(2) cubic crystal lattice (e.g., Mn3Ir and Mn3Pt) or a D0(19) hexagonal structure (e.g., Mn3Sn and Mn3Ge), exhibit a number of phenomena of interest to topological spintronics. Among the cubic systems, for example, tetragonally distorted Mn3Pt exhibits an intrinsic anomalous Hall effect (AHE). However, Mn3Pt only enters a noncollinear magnetic phase close to the stoichiometric composition and at suitably large thicknesses. Therefore, we turn our attention to Mn3Ir, the material of choice for use in exchange bias heterostructures. In this letter, we investigate the magnetic and electrical transport properties of epitaxially grown, face-centered-cubic gamma-Mn3Ir thin films with (111) crystal orientation. Relaxed films of 10 nm thickness exhibit an ordinary Hall effect, with a hole-type carrier concentration of (1.500 +/- 0.002) x 10(23) cm(-3). On the other hand, TEM characterization demonstrates that ultrathin 3 nm films grow with significant in-plane tensile strain. This may explain a small net magnetic moment, observed at low temperatures, shown by X-ray magnetic circular dichroism spectroscopy to arise from uncompensated Mn spins. Being of the order of 0.02 mu(B)/atom, this dominates electrical transport behavior, leading to a small AHE and negative magnetoresistance. These results are discussed in terms of crystal microstructure and chiral domain behavior, with spatially resolved XML(C)D-PEEM supporting the conclusion that small antiferromagnetic domains, <20nm in size, with differing chirality account for the absence of observed Berry curvature driven magnetotransport effects. Published under license by AIP Publishing.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | MAGNETORESISTANCE; TORQUE; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Back > Group Christian Back Physics > Institute of Experimental and Applied Physics > Chair Professor Back > Group Josef Zweck |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 01 Apr 2020 05:09 |
| Last Modified: | 01 Apr 2020 05:09 |
| URI: | https://pred.uni-regensburg.de/id/eprint/26454 |
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