Near-field imaging of high-frequency magnetic fields with calorimetric cantilever probes

Calorimetric probes for near-field imaging of high-frequency (1-20 GHz) magnetic fields were fabricated by depositing patterned metal structures on micromachined, dielectric multilayer cantilevers. In the presence of high-frequency magnetic fields, the metal structures are heated via the generation of eddy currents or via ferromagnetic resonance (FMR). Measurement of the resulting cantilever deflection as a function of probe position produces a map of the microwave power distribution. Comparative measurements from probes with 5 and 10 mu m Au rings show that the rings are the active area for eddy current generation. Probes with 10 mu m square permalloy patches function in both the eddy current and FMR imaging modes. (C) 2006 American Institute of Physics.