Project A7 - Electrically Modulated Magnetoelectric Sensors

Research of the first funding period has shown that electrically modulated mesoscopic ME composites, targeting especially high frequency mechanical resonances, far higher than flexural modes, lead to dramatically enhanced converse ME effect. This is observed by vibrometry as well as in-situ MOKE studies. Exciting high frequency resonances of an ME composite immersed in an inductor while matching the inductive self-resonance to the mechanical resonance provides intrinsic amplification towards the converse ME effect, thus forming an overall resonant circuit. This resonant circuit proves very sensitive to external magnetic fields: 215 pT/Hz^1/2 are obtained at DC, reaching 73 pT/Hz^1/2 at 10 Hz. The use of magnetostrictive (MS) materials involving sophisticated exchange bias leads to even lower detection limits of 30 pT/Hz^1/2 at 10 Hz. As high frequency resonances typically undergo less damping than flexural modes, high mechanical quality factors are readily reached at ambient pressure. The combination of high frequencies and high mechanical quality factors leads to increased available sensing bandwidth on the order of several hundred Hertz, suitable to biomagnetic as well as deep brain stimulation (DBS) application requirements.

The work of the second funding period will be focused on deriving a comprehensive signal-to-noise model of the electrically modulated ME sensor. The work on the model will be performed in close collaboration with modelling and characterization (projects A8, A10, and B1). More detailed objectives are to investigate the influence of

• the homogeneity of the resonance mode,
• the nature of the magnetization reversal processes,
• the orientation of the easy axis, and
• the resonance frequency of the U mode on the signal and the noise of these sensors.

Finally, the influence of the size of the sensor on its overall performance will be investigated, as many biomagnetic applications require a high spatial resolution.

Involved Researchers

Person		Role
	Prof. Dr. Eckhard Quandt Materials Science Inorganic Functional Materials	Project lead
	Dr. Felix Schlichting Materials Science Multicomponent Materials	Doctoral researcher

Role within the Collaborative Research Centre

The Collaborative Research Centre 1261 “Magnetoelectric Sensors: From Composite Materials to Biomagnetic Diagnostics” spans a wide range of projects: from materials research to sensor concepts to signal processing and finally to applications. Because this project deals with one of the sensor concepts, it is fully integrated within this research chain and we will have intense collaborations with materials research, sensor systems, and especially with the transfer project. Specifically, this sensor concept reaches all secondary requirements demanded by applications such as high bandwidth, acoustic immunity, and no required bias field, which makes it particularly relevant to T1.

Project-related Publications

E. Elzenheimer, P. Hayes, L. Thormählen, E. Engelhardt, A. Zaman, E. Quandt, N. Frey, M. Höft, G. Schmidt: Investigation of Converse Magnetoelectric Thin Film Sensors for Magnetocardiography, IEEE Sensors Journal Print ISSN, pp. 5660-5669, 2023.

J. Arbustini, J. Muñoz, H. Wang, E. Elzenheimer, J. Hoffmann, L. Thormählen, P. Hayes, F. Niekiel, H. Heidari, M. Höft, E. Quandt, G. Schmidt, A. Bahr: MEMS Magnetic Field Source for Frequency Conversion Approaches for ME Sensors, BMT2022 , Joint Annual Conference of the Austrian, German and Swiss Societies for Biomedical Engineering, 2022.

E. Elzenheimer, C. Bald, E. Engelhardt, J. Hoffmann, P. Hayes, J. Arbustini, A. Bahr, E. Quandt, M. Höft, G. Schmidt: Quantitative Evaluation for Magnetoelectric Sensor Systems in Biomagnetic Diagnostics, MDPI Sensors, vol. 22, no. 3, 1018, 2022.

X. Liang, A. Matyushov, P. Hayes, V. Schell, C. Dong, H. Chen, Y. He, A. Will-Cole, E. Quandt, P. Martins, J. McCord, M. Medarde, S. Lanceros-Méndez, S. van Dijken, N. X. Sun, J. Sort: Roadmap on Magnetoelectric Materials and Devices, IEEE Transactions on Magnetics, vol. 57, issue 8, 9446997, 2021.

D. Laumann, C. Enzingmüller, I. Parchmann, E. Quandt, P. Hayes: Magnetostriction Measurements with a Low-Cost Magnetostrictive Cantilever Beam, American Journal of Physics, 88(3), 2020.

S. M. Curtis, N. Wolff, D. Dengiz, H. Lewitz, J. Jetter, L. Bumke, P. Hayes, E. Yarar, L. Thormählen, L. Kienle, D. Meyners, E. Quandt: Integration of AlN Piezoelectric Thin Films on Ultralow Fatigue TiNiCu Shape Memory Alloys, Journal of Materials Research 35, no. 10, pp. 1298–1306, 2020.

D. Laumann, P. Hayes, C. Enzingmüller, E. Quandt, I. Parchmann: Magnetostriction Measurements with a Low-Cost Magnetostrictive Cantilever Beam, American Journal of Physics, vol. 88, issue 6, 064036, 2019.

P. Hayes, M. Jovičević Klug, S. Toxværd, P. Durdaut, V. Schell, A. Teplyuk, D. Burdin, A. Winkler, R. Weser, Y. Fetisov, M. Höft, R. Knöchel, J. McCord, E. Quandt: Converse Magnetoelectric Composite Resonator for Sensing Small Magnetic Fields, Scientific Reports, vol. 9, 16355, 2019.

Y. K. Fetisov, D. A. Burdin, N. A. Ekonomov, L. Y. Fetisov, A. A. Berzin, P. Hayes, E. Quandt: Bistability in a Multiferroic Composite Resonator, Applied Physics Letters, vol. 113, issue 2, 022903, 2018.

P. Hayes, V. Schell, S. Salzer, D. Burdin, E. Yarar, A. Piorra, R. Knöchel, Y. K. Fetisov, E. Quandt: Electrically Modulated Magnetoelectric AlN/FeCoSiB Film Composites for DC Magnetic Field Sensing, Journal of Physics D: Applied Physics, vol. 51, no. 35, 354002, 2018.

P. Hayes, S. Salzer, J. Reermann, E. Yarar, V. Röbisch, A. Piorra, D. Meyners, M. Höft, R. Knöchel, G.Schmidt, E. Quandt: Electrically Modulated Magnetoelectric Sensors, Applied Physics Letters, 108(18), 2016.

N. O. Urs, B. Mozooni, P. Mazalski, M. Kustov, P. Hayes, S. Deldar, E. Quandt,J. McCord: Advanced Magneto-optical Microscopy: Imaging from Picoseconds to Centimeters-imaging Spin Waves and Temperature Distributions, AIP Advances, 6(5), 055605, 2016.