Acoustically driven ferromagnetic resonance in magnetoelectric thin film materials for high performance magnetometry (27/06/24)
Speaker and Affliation:
Dr. Kumar Srinivasan,
Director of Materials Engineering at Sonera, Berkeley, CA, USA
When?
27th June, 2024 (Thursday), 04.00 PM (India Standard Time)
Where
KPA Auditorium, Dept. of Materials Engineering, IISc, Bangalore
Abstract
High-performance magnetometers capable of sub-nTesla detectability with reduced SWaP-C (size, weight, power and cost) are key towards building advanced human-machine interface sensors. To meet these objectives, Sonera has developed novel surface acoustic wave (SAW) based delay-line sensors that leverage the coupling between SAW and spin waves in a synthetic multiferroic heterostructure to create an extremely efficient method for energy transduction. In this sensing modality, termed acoustically-driven ferromagnetic resonance (ADFMR), a thin magnetic film strip is deposited between two pairs of lithographically patterned interdigital transducers, and is excited into resonance through elastic interactions with the travelling SAW. Any small external magnetic field will shift the magnetic film out of resonance, and alter the transmission characteristics of the SAW, allowing for very high sensitivity. In this talk, I will examine the design considerations of the magnetoelectric layer for ADFMR based magnetometry, with particular emphasis on the growth and optimization of FeGaB based magnetostrictive thin films on yz-cut LiNbO3 piezoelectric substrates. I will conclude with examples of how the design and properties of the magnetoelectric layer impact the ADFMR device characteristics such as rf power absorption, sensitivity and the sensor’s limit of detection.
Speaker’s Bio:
Dr. Kumar Srinivasan is currently the Director of Materials Engineering at Sonera, where he is leading the materials technology research program and development operations. Based in Berkeley, California, Sonera is an early-stage technology company developing non-invasive human-machine interface sensors for biomagnetics sensing applications. Prior to joining Sonera, Dr. Kumar was at Western Digital in San Jose, California where he helped to develop state-of-the-art thin film magnetic material technologies for data storage applications. He has authored/co-authored more than 40 peer-reviewed publications, one book chapter, been issued more than 20 patents/trade secrets and delivered invited talks at multiple forums such as MMM, MRS, IEEE and ISIM. He is a Senior Member of the IEEE and has served on numerous conference organizing committees such as MMM, Intermag and TMRC. He holds a B.Tech degree from IIT Madras and M.S. & Ph.D. degrees in Materials Science & Engineering from Carnegie Mellon University.