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Ferromagnetic Resonance Spectroscopy with a Micromechanical Calorimeter Sensor



John M. Moreland, M. Loehndorf, Pavel Kabos, Robert McMichael


We describe a new type of ferromagnetic resonance (FMR) spectroscopy that is based on a calorimeter sensor. We use an atomic force microscopy cantilever coated with a ferromagnetic thin film as a bimaterial sensor to measure absorption of microwaves at 9.17 GHz. The spectra show a peak in the cantilever deflection as a function of applied magnetic field corresponding to a peak in the absorbed microwave power that occurs at the FMR resonance of the ferromagnetic film. The saturation magnetization M3ff and the damping factor α were determined from the FMR microwave absorption spectra for Co, NiFe, and Ni thin films. The data correlate well with conventional FMR spectra taken with a tuned cavity spectrometer. Our instrument can detect magnetic moments as small as 1.3 c 10-12 A m2 (1.3X10-9 emu) with prospects for snesitivity improvements to the 1 x 10u-16^ Am2 (1X10-12emu) level. The technique provides a potentially superior way to make quantitative measurements of saturation magnetization of thin-film samples with very small total magnetic moments.
Review of Scientific Instruments


atomic force microscopy, bimetallic thermal sensor, ferromagnetic resonance, magnetic moments, thermal absorption, thin-film samples


Moreland, J. , Loehndorf, M. , Kabos, P. and McMichael, R. (2000), Ferromagnetic Resonance Spectroscopy with a Micromechanical Calorimeter Sensor, Review of Scientific Instruments, [online], (Accessed July 15, 2024)


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Created July 31, 2000, Updated October 12, 2021