Electrostatic transfer of sub-micron magnetic particles onto cantilevers using a focused ion beam system

TL;DR

This paper introduces a focused-ion-beam-assisted electrostatic method for attaching magnetic nanoparticles to cantilevers, enabling precise, damage-minimized fabrication of custom magnetic tips for advanced microscopy.

Contribution

The authors develop a novel electrostatic transfer technique that allows precise, damage-minimized attachment of magnetic nanoparticles to cantilevers, expanding fabrication possibilities for magnetic resonance force microscopy.

Findings

Successfully transferred magnetic particles from 460 nm to 2.8 μm in size.

Enabled fabrication of various tip shapes, sizes, and materials previously unachievable.

Confirmed minimal ion-beam damage through Monte Carlo simulations.

Abstract

In this paper, we present a focused-ion-beam-assisted method for preparing magnet tips for magnetic resonance force microscopy measurements. The method electrostatically transfers prefabricated magnetic nanoparticles to microcantilevers, achieving precise control over the magnet overhang past the cantilever leading edge while minimizing the fabrication damage to the leading edge of the tip magnet. We demonstrate successful fabrication of magnets ranging in size from 460 nm to 2.8 um. These magnets were affixed to two types of cantilevers: silicon cantilevers with a spring constant of 800 uN/m, and single-crystal silicon cantilevers with a spring constant of 30 uN/m. We show that the electrostatic transfer method enables a wide variety of tip shapes, sizes, and materials that were previously not possible with conventional fabrication methods. The transfer procedure allows us to prefabricate the desired particle geometry with minimal ion-beam damage, as confirmed by Monte Carlo simulations. We show that the technique is versatile and can be used to fabricate custom-tipped cantilevers for a broader range of scanning probe techniques.