Nanowire magnetic force sensors fabricated by focused electron beam induced deposition

TL;DR

This paper demonstrates the use of magnetic nanowires fabricated by focused electron beam induced deposition as highly sensitive scanning magnetic force sensors capable of imaging weak magnetic fields and current patterns.

Contribution

It introduces a novel application of FEBID-grown magnetic nanowires as customizable, high-quality magnetic sensors for detailed magnetic imaging.

Findings

Nanowires exhibit high-quality mechanical modes.

Nanowires have strong remanent magnetization.

Sensors successfully image magnetic fields and current patterns.

Abstract

We demonstrate the use of individual magnetic nanowires (NWs), grown by focused electron beam induced deposition (FEBID), as scanning magnetic force sensors. Measurements of their mechanical susceptibility, thermal motion, and magnetic response show that the NWs posses high-quality flexural mechanical modes and a strong remanent magnetization pointing along their long axis. Together, these properties make the NWs excellent sensors of weak magnetic field patterns, as confirmed by calibration measurements on a micron-sized current-carrying wire and magnetic scanning probe images of a permalloy disk. The flexibility of FEBID in terms of the composition, geometry, and growth location of the resulting NWs, makes it ideal for fabricating scanning probes specifically designed for imaging subtle patterns of magnetization or current density.