Magnetization damping is essential for data storage and retrieval at GHz data rates in disk drives, MRAM chips arid other magnetoelectronic devices. In disk drives, the write head materials, media and read head must all be able to perform well oii nanosecond time scales. For measurement of magnetic damping parameters. ferromagnetic resonance (FMR,) is the dominant technique, but the raw linewidth data is often clouded by the presence of inhomogeneities. Our modeling of ferromagnetic resonance spectra in mhoniogeneous thin films takes a novel approach to a problem that for several decades has been solved only for weak irthomogeneities. Our new model mvolves solving fur the normal modes of arm inhomogeimeous film and calculating the absorption spectrum from all of the modes. This model provides the theoretical basis for studying the intrinsic damping processes through FMR linewidth measurements, and ultimately for delivering the needed data on magnetic damping to induslry.
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