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arXiv · 2004.07888

Magnetic domain wall substructures in Pt/Co/Ni/Ir multi-layers

Maxwell Li·Arjun Sapkota·Anish Rai·Ashok Pokhrel·Tim Mewes·Claudia Mewes·Di Xiao·Marc De Graef·Vincent Sokalski
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Abstract

We examine the substructures of magnetic domain walls (DWs) in [Pt/(Co/Ni)$_M$/Ir]$_N$ multi-layers using a combination of micromagnetic theory and Lorentz transmission electron microscopy (LTEM). Thermal stability calculations of Q=$\pm$1 substructures (2-$\pi$ vertical Bloch lines (VBLs) and DW skyrmions) were performed using a geodesic nudged elastic band (GNEB) model, which supports their metastability at room temperature. Experimental variation in strength of the interfacial Dzyaloshinskii-Moriya interaction (DMI) and film thickness reveals conditions under which these substructures are present and enables the formation of a magnetic phase diagram. Reduced thickness is found to favor Q=$\pm$1 substructures likely due to the suppression of hybrid DWs. The results from this study provide an important framework for examining 1-D DW substructures in chiral magnetic materials.

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Maxwell Li, Arjun Sapkota, Anish Rai, Ashok Pokhrel, Tim Mewes, Claudia Mewes, Di Xiao, Marc De Graef, Vincent Sokalski. 2020-04-16. Magnetic domain wall substructures in Pt/Co/Ni/Ir multi-layers. https://doi.org/10.1063/5.0056100

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