Dual-Functional 3D-Nanoprinted AFM Probes for Correlative Magnetic and Conductive Characterization

Based on previously reported 3D nanoprinted probes for magnetic force microscopy (MFM), a new class of dual-functional atomic force microscopy (AFM) probes - termed MC-Probes - is presented that integrates magnetic (M) and conductive (C) functionality in a single, monolithic structure. 3D nanoprinting via Focused Electron Beam Induced Deposition allows direct exploitation of the intrinsic magnetic and conductive properties of the employed Co₃Fe precursor. The coating-free probes feature sub-10 nm apex radii combined with a mechanically robust pillar geometry, designed to support both contact and tapping-mode operation depending on the cantilever choice. Comprehensive characterization reveals electrical resistivity ≈ 2 × 10³ · µΩ · cm and full tip resistances of, ∼ 1 - 10kΩ comparable to commercial conductive probes. Mechanical tests confirm apex durability under contact-mode loads up to. 3 - 4N · m^-1 MC-Probe functionality is demonstrated through conductive AFM (CAFM) and MFM measurements performed in the FUSIONScope™ on custom SiO₂/Au/Co₃Fe test structures. While the current cantilever availability required separate cantilevers optimized for contact and tapping operation, the results establish the foundation for future single-cantilever dual-mode integration. Beyond the present study, MC-Probes open promising perspectives for streamlined correlative investigations across CAFM, MFM, Kelvin probe force microscopy, electrostatic force microscopy, scanning spreading resistance microscopy, and related advanced AFM modes.