TY  - JOUR
AU  - Llandro, Justin
AU  - Love, David M.
AU  - Kovács, András
AU  - Caron, Jan
AU  - Vyas, Kunal N.
AU  - Kákay, Attila
AU  - Salikhov, Ruslan
AU  - Lenz, Kilian
AU  - Fassbender, Jürgen
AU  - Scherer, Maik R. J.
AU  - Cimorra, Christian
AU  - Steiner, Ullrich
AU  - Barnes, Crispin H. W.
AU  - Dunin-Borkowski, Rafal E.
AU  - Fukami, Shunsuke
AU  - Ohno, Hideo
TI  - Visualizing Magnetic Structure in 3D Nanoscale Ni–Fe Gyroid Networks
JO  - Nano letters
VL  - 20
IS  - 5
SN  - 1530-6992
CY  - Washington, DC
PB  - ACS Publ.
M1  - FZJ-2020-02732
SP  - 3642 - 3650
PY  - 2020
AB  - Arrays of interacting 2D nanomagnets display unprecedented electromagnetic properties via collective effects, demonstrated in artificial spin ices and magnonic crystals. Progress toward 3D magnetic metamaterials is hampered by two challenges: fabricating 3D structures near intrinsic magnetic length scales (sub-100 nm) and visualizing their magnetic configurations. Here, we fabricate and measure nanoscale magnetic gyroids, periodic chiral networks comprising nanowire-like struts forming three-connected vertices. Via block copolymer templating, we produce Ni75Fe25 single-gyroid and double-gyroid (an inversion pair of single-gyroids) nanostructures with a 42 nm unit cell and 11 nm diameter struts, comparable to the exchange length in Ni–Fe. We visualize their magnetization distributions via off-axis electron holography with nanometer spatial resolution and interpret the patterns using finite-element micromagnetic simulations. Our results suggest an intricate, frustrated remanent state which is ferromagnetic but without a unique equilibrium configuration, opening new possibilities for collective phenomena in magnetism, including 3D magnonic crystals and unconventional computing.
LB  - PUB:(DE-HGF)16
C6  - pmid:32250635
UR  - <Go to ISI:>//WOS:000535255300092
DO  - DOI:10.1021/acs.nanolett.0c00578
UR  - https://juser.fz-juelich.de/record/878263
ER  -