posted on 2021-12-09, 19:16authored byUmberto Celano, Hai Zhong, Florin Ciubotaru, Laurentiu Stoleriu, Alexander Stark, Peter Rickhaus, Felipe Fávaro de Oliveira, Mathieu Munsch, Paola Favia, Maxim Korytov, Patricia Van Marcke, Patrick Maletinsky, Christoph Adelmann, Paul van der Heide
Magnetic
nanowires (NWs) are essential building blocks of spintronics
devices as they offer tunable magnetic properties and anisotropy through
their geometry. While the synthesis and compositional control of NWs
have seen major improvements, considerable challenges remain for the
characterization of local magnetic features at the nanoscale. Here,
we demonstrate nonperturbative field distribution mapping in ultrascaled
magnetic nanowires with diameters down to 6 nm by scanning nitrogen-vacancy
magnetometry. This enables localized, minimally invasive magnetic
imaging with sensitivity down to 3 μT Hz–1/2. The imaging reveals the presence of weak magnetic inhomogeneities
inside in-plane magnetized nanowires that are largely undetectable
with standard metrology and can be related to local fluctuations of
the NWs’ saturation magnetization. In addition, the strong
magnetic field confinement in the nanowires allows for the study of
the interaction between the stray magnetic field and the nitrogen-vacancy
sensor, thus clarifying the contrasting formation mechanisms for technologically
relevant magnetic nanostructures.