Regensburg 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MA: Fachverband Magnetismus
MA 23: Magnetic Domain Walls
MA 23.5: Talk
Wednesday, September 7, 2022, 10:30–10:45, H48
Strain-controlled Domain Wall injection into nanowires for sensor applications — •Giovanni Masciocchi1,2, Mouad Fattouhi3, Andreas Kehlberger2, Luis López Díaz3, and Mathias Kläui1 — 1Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany — 2Sensitec GmbH, 55130 Mainz, Germany — 3Department of Applied Physics, Universidad de Salamanca, E-37008 Salamanca, Spain
In this study, we address a well-known challenge in magnetic sensor development, which is the effect of packaging-induced strain on the sensor properties. While previously the field operation window has only been studied in idealized operation conditions, in real devices further external factors such as strain play a role.
In this experimental work, we investigate the injection of a 180° domain wall from a nucleation pad into a nanowire, as typically used for domain wall-based sensors, while straining the device along selected directions. Combining our experimental measurements by Kerr microscopy with micromagnetic simulations, we find that strain, regardless of its direction, increases the domain wall injection field due to the magnetoelastic coupling of the magnetic material. The above-described observations can be explained by an effective strain-induced anisotropy in the device.
We find additionally that a careful material preparation, comprising of an annealing step, can reduce the effective anisotropy caused by the strain in the magnetic layer. With this we show that a device free of magnetostrictive behavior can be achieved.