Complex Three-Dimensional Magnetic Ordering in Segmented Nanowire Arrays

Published

July 12, 2017

Author(s)

Alexander J Grutter, Kathryn Krycka, Elena V. Tartakovskaya, Julie A. Borchers, K. Sai Madhukar Reddy, Eduardo Ortega, Arturo Ponce, Bethanie J. H. Stadler

Abstract

The first comprehensive three-dimensional picture of magnetic ordering in high-density arrays of segmented FeGa/Cu nanowires is experimentally realized through the application of Polaris small angle neutron scattering. The competing energetics of dipolar interactions, shape anisotropy, and Zeeman energy in concert stabilize a highly tunable spin structure which depends heavily on the applied field and sample geometry. Consequently, we observe ferromagnetic and antiferromagnetic interactions both among wires and between segments within individual wires. The resulting magnetic structure for our nanowire sample in a low field is a fan with magnetization perpendicular to the wire axis that aligns nearly antiparallel from one segment to the next along the wire axis. Additionally, while the low-field interwire coupling is ferromagnetic, application of a field tips the moments toward the nanowire axis, resulting in highly-frustrated antiferromagntic stripe patterns in the hexagonal nanowire lattice. Theoretical calculations confirm these observations, providing insight into the competing interactions and resulting stability windows for a variety of ordered magnetic structures. These results provide a roadmap for designing high density magnetic nanowire arrays for spintronic device applications.

Citation

ACS Nano

Volume

2017

Issue

11

Pub Type

Journals

Download Paper

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Keywords

Nanowire, Magnetism, SANS

Citation

, A. , , K. , , E. , Borchers, J. , , K. , Ortega, E. , Ponce, A. and H., B. (2017), Complex Three-Dimensional Magnetic Ordering in Segmented Nanowire Arrays, ACS Nano, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923573 (Accessed March 13, 2025)