Additive Manufacturing of Co3Fe Nano-Probes for Magnetic Force Microscopy

Abstract

Magnetic force microscopy (MFM) is a powerful extension of atomic force microscopy (AFM), which mostly uses nano-probes with functional coatings for studying magnetic surface features. Although well established, additional layers inherently increase apex radii, which reduce lateral resolution and also contain the risk of delamination, rendering such nano-probes doubtful or even useless. To overcome these limitations, we now introduce the additive direct-write fabrication of magnetic nano-cones via focused electron beam-induced deposition (FEBID) using an HCo3Fe(CO)12 precursor. The study first identifies a proper 3D design, confines the most relevant process parameters by means of primary electron energy and beam currents, and evaluates post-growth procedures as well. That way, highly crystalline nano-tips with minimal surface contamination and apex radii in the sub-15 nm regime are fabricated and benchmarked against commercial products. The results not only reveal a very high performance during MFM operation but in particular demonstrate virtually loss-free behavior after almost 8 h of continuous operation, thanks to the all-metal character. Even after more than 12 months of storage in ambient conditions, no performance loss is observed, which underlines the high overall performance of the here-introduced FEBID-based Co3Fe MFM nano-probes.

Focused Helium Ion and Electron Beam-Induced Deposition of Organometallic Tips for Dynamic Atomic Force Microscopy of Biomolecules in Liquid

“…Moreover, as has been shown in a recent FEBID study, iron-containing precursors can be used to grow magnetic tips onto HS-AFM cantilevers and employed for magnetic force microscopy (MFM) in liquid . Bimetallic iron–cobalt magnetic FEBID tips have also been demonstrated . Tips such as these could be used for in-liquid MFM of magnetic biological structures, further underscoring the versatility of the FEBID and FIBID tip fabrication methods.…”

“…23 Bimetallic iron−cobalt magnetic FEBID tips have also been demonstrated. 24 Tips such as these could be used for in-liquid MFM of magnetic biological structures, 25 further underscoring the versatility of the FEBID and FIBID tip fabrication methods.…”

A Review of the Current State of Magnetic Force Microscopy to Unravel the Magnetic Properties of Nanomaterials Applied in Biological Systems and Future Directions for Quantum Technologies

“…(1) Cylindrical pillars that taper to a sharp tip apex with radii of less than 10 nm [315,327] (Figure 9h). (2) Customizable pillar heights that are defined by the electron exposure conditions, allowing for tips with high aspect ratios (Figure 9i), which is beneficial for a quasimonopole behavior [328].…”

Gas-Phase Synthesis of Iron Silicide Nanostructures Using a Single-Source Precursor: Comparing Direct-Write Processing and Thermal Conversion

“…In the precursor-limited regime, the molecular sources are fragmented, resulting in a deposit, but at the same time, sputtering will remove parts of the deposit or substrate material . Differences in the ion beam scanning strategies will impact the final appearance of the deposit morphology such as the formation of tubular nanostructures in FIBID instead of a solid nanowire as observed for FEBID, when single-spot deposition is used. − …”