TY - JOUR
T1 - Domain Wall Propagation and Pinning Induced by Current Pulses in Cylindrical Modulated Nanowires
AU - Bran, Cristina
AU - Fernandez-Roldan, Jose Angel Fernandez
AU - Moreno, Julian
AU - Fraile Rodriguez, Arantxa
AU - Perez del Real, Rafael
AU - Asenjo, Agustina
AU - Saugar, Elias
AU - Marqués-Marchán, Jorge
AU - Mohammed, Hanan
AU - Foerster, Michael
AU - Aballe, Lucia
AU - Kosel, Jürgen
AU - Vazquez, Manuel
AU - Chubykalo-Fesenko, Oksana
N1 - KAUST Repository Item: Exported on 2023-04-13
Acknowledgements: This work was supported by the grants PID2019-108075RB-C31 funded by Ministry of Science and Innovation MCIN/AEI/ 10.13039/501100011033 and S2018/NMT-4321 NANOMAGCOST-CM funded by the Government of Madrid Region, Spain. We acknowledge the service from the MiNa Laboratory at IMN, and funding from CM (project SpaceTec, S2013/ICE2822), MINECO (project CSIC13-4E-1794) and EU (FEDER, FSE).
PY - 2023/4/10
Y1 - 2023/4/10
N2 - The future developments of 3D magnetic nanotechnology require the control of domain wall dynamics by means of current pulses. While this has been extensively studied in 2D magnetic strips (planar nanowires), few reports exist in cylindrical geometry, where Bloch Point domain walls are expected to have intriguing properties. Here we report this investigation in cylindrical magnetic Ni nanowires with geometrical notches. Experimental work based on synchrotron X-ray magnetic circular dichroism (XMCD) combined with photoemission electron microscopy (PEEM) indicates that large current densities induce domain wall nucleation while smaller currents move domain walls preferably antiparallel to the current direction. In the region where no pinning centers are present we found domain wall velocity of about 1 km/s. Thermal modelling indicates that large current densities temporarily raise the temperature in the nanowire above the Curie temperature leading to nucleation of domain walls during the system cooling. Micromagnetic modelling with spin-torque effect shows that for intermediate current densities Bloch Point domain walls with chirality parallel to the Oersted field propagate antiparallel to the current direction. In other cases, domain walls can be bounced from the notches and/or get pinned outside their positions. We thus find that current is not only responsible for the domain wall propagation but is also a source of pinning due to the Oersted field action.
AB - The future developments of 3D magnetic nanotechnology require the control of domain wall dynamics by means of current pulses. While this has been extensively studied in 2D magnetic strips (planar nanowires), few reports exist in cylindrical geometry, where Bloch Point domain walls are expected to have intriguing properties. Here we report this investigation in cylindrical magnetic Ni nanowires with geometrical notches. Experimental work based on synchrotron X-ray magnetic circular dichroism (XMCD) combined with photoemission electron microscopy (PEEM) indicates that large current densities induce domain wall nucleation while smaller currents move domain walls preferably antiparallel to the current direction. In the region where no pinning centers are present we found domain wall velocity of about 1 km/s. Thermal modelling indicates that large current densities temporarily raise the temperature in the nanowire above the Curie temperature leading to nucleation of domain walls during the system cooling. Micromagnetic modelling with spin-torque effect shows that for intermediate current densities Bloch Point domain walls with chirality parallel to the Oersted field propagate antiparallel to the current direction. In other cases, domain walls can be bounced from the notches and/or get pinned outside their positions. We thus find that current is not only responsible for the domain wall propagation but is also a source of pinning due to the Oersted field action.
UR - http://hdl.handle.net/10754/682324
UR - http://pubs.rsc.org/en/Content/ArticleLanding/2023/NR/D3NR00455D
U2 - 10.1039/d3nr00455d
DO - 10.1039/d3nr00455d
M3 - Article
C2 - 37092798
SN - 2040-3364
JO - Nanoscale
JF - Nanoscale
ER -