Project A7 - Electrically Modulated Magnetoelectric Sensors

Extensive research conducted during previous funding periods has revealed compelling evidence supporting the utilization of electrically modulated magnetoelectric composites for special high-frequency mechanical resonances, commonly referred to as U-modes. These U-modes dynamically and substantially modify the effective anisotropy of the magnetic layers and, thus, exhibit superior performance compared to flexural modes. The findings highlight the remarkable enhancement achieved in the overall performance of electrically modulated magnetoelectric composites when targeting these specific resonances. In this sensor concept the high frequency resonances are excited with a piezoelectric layer in order to exploit the converse magnetoelectric effect, while the sensor is immersed in a pick-up coil, using the induced voltage as the sensor signal.

In the second funding period the use of exchange biased multilayers dedicated for the converse magnetoelectric effect resulted in a significant improvement of the limit of detection (LOD). The LODs for sensors using single layer magnetostrictive materials (200 pT/Hz1/2 at DC and 70 pT/Hz1/2 at 10 Hz) could be improved by an order of magnitude to 16 pT/Hz1/2 at DC and 7.5 pT/Hz1/2 at 10 Hz. These LODs in combination with the bandwidth of about 1 kHz have led to the fact that these sensors were applied for first magnetocardiological investigations. In the upcoming third funding period, our research endeavors will be dedicated to advancing the attainable limits of detection (LODs) through the utilization of special magnetic multilayer films. This pursuit will be conducted in close collaboration with project A1, which has the aim to enhance LODs significantly. Additionally, our focus will involve elevating the frequency range of the U-mode employed to the low MHz range for an expected further improvement of performance as the sensitivity of resonant sensors scale with the resonance frequency. To achieve an overall improvement of the LOD, we will furthermore explore novel resonator designs in collaboration with A8 that promote homogeneous stress states within the dimensions of the pick-up coil. By investigating alternative clamping concepts, we aim to curtail undesirable factors such as drift in the resonance frequency, which can arise due to variations in temperature. Together, these research directions aim to push the boundaries of LODs, enabling more sensitive and accurate magnetic field sensing capabilities. In collaboration with project B10, these improved sensors will be used for more advanced magnetocardiological investigations requiring e. g. unaveraged measurements. According to the specific requirements to perform these measurements, the property profile will be adapted accordingly.

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 with application projects in the project area B.

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.