Synthetic ferrimagnet nanowires with very low critical current density for coupled domain wall motion

DOI: 10.1038/s41598-017-01748-7

Authors: Serban Lepadatu (University of Leeds; University of Central Lancashire) , Henri Saarikoski (RIKEN Center for Emergent Matter Science (CEMS)) , Robert Beacham (University of Glasgow) , Maria Jose Benitez (University of Glasgow; Escuela Politécnica Nacional) , Thomas A. Moore (University of Leeds) , Gavin Burnell (University of Leeds) , Satoshi Sugimoto (University of Leeds) , Daniel Yesudas (University of Leeds) , May C. Wheeler (University of Leeds) , Jorge Miguel (Diamond Light Source) , Sarnjeet S. Dhesi (Diamond Light Source) , Damien Mcgrouther (University of Glasgow) , Stephen Mcvitie (University of Glasgow) , Gen Tatara (RIKEN Center for Emergent Matter Science (CEMS)) , Christopher Marrows (University of Leeds)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 7

State: Published (Approved)
Published: May 2017
Diamond Proposal Number(s): 6709

Abstract: Domain walls in ferromagnetic nanowires are potential building-blocks of future technologies such as racetrack memories, in which data encoded in the domain walls are transported using spin-polarised currents. However, the development of energy-efficient devices has been hampered by the high current densities needed to initiate domain wall motion. We show here that a remarkable reduction in the critical current density can be achieved for in-plane magnetised coupled domain walls in CoFe/Ru/CoFe synthetic ferrimagnet tracks. The antiferromagnetic exchange coupling between the layers leads to simple Néel wall structures, imaged using photoemission electron and Lorentz transmission electron microscopy, with a width of only ~100 nm. The measured critical current density to set these walls in motion, detected using magnetotransport measurements, is 1.0 × 1011 Am−2, almost an order of magnitude lower than in a ferromagnetically coupled control sample. Theoretical modelling indicates that this is due to nonadiabatic driving of anisotropically coupled walls, a mechanism that can be used to design efficient domain-wall devices.

Journal Keywords: Applied physics; Electronic devices; Magnetic properties and materials; Spintronics

Diamond Keywords: Data Storage; Ferrimagnetism; Ferromagnetism; Spintronics

Subject Areas: Physics, Materials, Information and Communication Technology


Instruments: I06-Nanoscience (XPEEM)

Added On: 09/05/2017 12:16

Documents:
LepadatuSR_7_1640.pdf

Discipline Tags:

Quantum Materials Physics Electronics Components & Micro-systems Information & Communication Technologies Magnetism Materials Science

Technical Tags:

Microscopy Spectroscopy Electron Microscopy (EM) PhotoEmmission Electron Microscopy (PEEM) Circular Dichroism (CD) X-ray Magnetic Circular Dichroism (XMCD)