Effects of CoFeAl Alloy Composition on Magnetization Dynamics and Magnetic Thermal Transport
ORAL
Abstract
The lifetime of magnetic excitations in metals is governed by scattering rates between magnons and electrons. Recent investigations [1, 2] document how electronic band structure engineering in magnetic alloys allows for suppression of magnon scattering rates; e.g. Co0.25Fe0.75 thin-films display low magnetic damping (α ~ 10-4). My talk will focus on experimental measurements that demonstrate how ultrafast magnetization dynamics and transport properties of CoFeAl magnetic alloys depend on alloy composition. To explore the magnetization dynamics, I use a time-resolved MOKE set-up to observe ultrafast demagnetization in a few hundred femtoseconds followed by precessional dynamics. Through TDTR measurements, I check if lower electron-magnon scattering rates lead to improved thermal transport. My investigation sheds light on how magnon-electron scattering rates govern dynamics on femtosecond (ultrafast demagnetization), nanosecond (magnetic precession and damping), and microsecond time-scales (thermal transport of energy).
[1] Qin, H. J., et al. Nature communications 6 (2015): 6126. [2] Schoen, Martin AW, et al. Nature Physics 12.9 (2016): 839.
[1] Qin, H. J., et al. Nature communications 6 (2015): 6126. [2] Schoen, Martin AW, et al. Nature Physics 12.9 (2016): 839.
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Presenters
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Ramya Mohan
University of California, Riverside
Authors
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Ramya Mohan
University of California, Riverside
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Yiwei Sun
University of California, Riverside
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Suveen Mathaudhu
University of California, Riverside
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Sinisa Coh
University of California, Riverside, Materials Science and Engineering, University of California, Riverside
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Richard Wilson
Mechanical Engineering, University of California, Riverside, University of California, Riverside