Location: Bldg. 216, Rm. C012
Technology based on ferromagnetism plays a large role in modern life. For example, the hysteretic switching properties of magnetic films are used to store information on computer hard disk drives, and the dynamic properties of magnetic materials are crucial to the operation of microwave devices such as isolators and circulators that make radar possible. The hysteretic and dynamic properties of magnetism are expected to provide a foundation for future information handling and information storage technologies such as Magnetoresistive Random Access Memory (MRAM). To support the development of these future magneto-electronic technologies, the Nanomagnetic Dynamics Laboratory in the CNST provides tools for measuring magnetism dynamics in magnetic nanostructures. Recent projects include ferromagnetic resonance measurements of the magnetic properties of patterned thin film edges in large arrays of stripes fabricated using optical interference lithography. We also measure interactions between spin polarized currents and magnetization dynamics using nanofabricated microwave antennas that launch and detect spin waves in current-carrying ferromagnetic metal stripes. For these measurements, we use a cryogenic probe station with both microwave and DC probes and an integrated 0.5 T electromagnet. Spin wave transmission in these experiments is measured using a vector network analyzer with a frequency range up to 65 GHz. In order to measure the dynamic properties of individual nanostructures, we have constructed a ferromagnetic resonance force microscope. With this new scanning-probe instrument, we have detected ferromagnetic resonance in individual 100 nm-diameter, 20 nm-thick Ni80Fe20 nanostructures). Additional facilities for microscope operation include a room-temperature electromagnet, which provides applied fields of ± 2 T horizontally, and a variable temperature cryostat, with superconducting coils providing magnetic fields up to ± 5 T horizontally and ± 6 T vertically.