Local Excitation of Ferromagnetic Resonance and Its Spatially Resolved Detection With an Open-Ended Radio-Frequency Probe

A local excitation of ferromagnetic resonance (FMR) and its detection were performed by using an open-ended radio-frequency (RF) probe. The RF probe is composed of a coaxial cable transmitting broadband RF waves over 10 GHz and a sharp metal tip attached to its end. In the reflection spectrum (S ₁₁) taken on a polycrystalline yttrium iron garnet disk, three kinds of FMR absorption signals were observed. Intensity of the three signals showed strong spatial dependences over the sample, demonstrating the potential of the local probe for spatially resolved FMR microscopy.