Tuesday, October 9 2018

All day
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At least 20% of nearby main sequence stars are surrounded by disks of dusty material resulting from the collisional erosion of planetesimals, larger bodies similar to asteroids and comets in our own Solar System. The resulting dust can be observed via scattered light at visible to near-infrared wavelengths or thermal emission at mid-infrared to millimeter wavelengths.

Applications in magnetic information storage push inexorably towards higher speeds (GHz data rates) and smaller dimensions (TB capacities.) I will present measurements of two new effects in the GHz magnetization dynamics of device-related ferromagnetic films (Co, Ni81Fe19, Co40Fe40B20, 50nm and below), one relevant at fast timescales, one relevant at small dimensions, by some unconventional applications of ferromagnetic resonance (FMR). 1) At the highest FMR frequencies recorded for thin films, to 330 GHz, we find that a central assumption of magnetization dynamics breaks down.