Nanomaterials have attracted attention from a variety of fields. For example, magnetic nanowires (MNWs) can be used to identify and/or distinguish objects using their magnetic signatures: first-order reversal curves, hysteresis curves, angle-dependent coercivity, and ferromagnetic resonance (FMR). Among these, FMR is the fastest measurement, and it shows the potential to identify many high-frequency signatures simultaneously. In this work, iron, cobalt, and nickel MNW samples are fabricated by template-assisted pulsed electrodeposition and are measured individually and in combination using an FMR-identification (FMR-ID) labeling system. The FMR-ID system is then optimized using the FMR measurement results, the original and revised Kittel equations, and the magnetic properties of the MNWs. The most efficient FMR-ID systems will use DC bias fields (0-15 kOe) that are parallel to the nanowires and microwave frequencies of 20 GHz or above. These MNW-based FMR-ID labeling systems will be effective wherever small identification markers are needed.
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation under award number CMMI-1762884. Parts of this work were carried out in the Characterization Facility and the Minnesota Nano Center at the University of Minnesota, which received partial support from the NSF through the MRSEC and the National Nano Coordinated Infrastructure Network (NNCI award number ECCS-2025124) programs, respectively, and at the Institute for Rock Magnetism (IRM) at the University of Minnesota. The IRM is a U.S. National Multi-user Facility supported through the Instrumentation and Facilities program of the National Science Foundation, Earth Sciences Division, and by funding from the University of Minnesota.
- ferromagnetic resonance
- magnetic nanowires
- microwave absorption