Project A6

Microstructure and Structual Change of Magnetoelectric and Piezotronic Sensors

The combination of high resolution synchrotron-based X-ray scattering techniques and advanced transmission electron microscopy methods provides a unique view of the structural behavior of model sensors in situ and in operando. The synergetic combination covers a broad range of length scales, thus, enabling to investigate the local strain from the atomic to the µm dimensions. Here we plan to examine model sensors and their components, particularly as developed in projects A1 and A5 in identical and complimentary geometries allowing us to visualize strain and defect behavior in detail. These results will be returned to the project partners to ensure a knowledge-based enhancement of the sensor performance.


Bridget Murphy
Lead of project A6
Lorenz Kienle
Prof. Dr. rer. nat.
Lead of project A6
Niklas Wolff
Postdoctoral researcher


Role within the Collaborative Research Centre

The unique combination of synchrotron based techniques and atomically resolved electron microscopy enables us to analyze the piezotronic (A5) and multilayer materials (A1) and sensors on all relevant length scales, ex situ and in situ. A6 develops new and advanced in situ examination methods in close collaboration with these projects. Moreover, A6 establishes the competence center for advanced structural and nanoanalytical research within the CRC. In order to identify new scientifically demanding tasks which cannot be foreseen at the present date, A6 also provides preliminary nanoanalytical examinations for several other projects, like A2, A3/A7, A8, and Z1. Additional characterization of samples that is not part of the work packages will be performed by permanent staff, e.g. of the TEM center (Dr. Schürmann). Scheduled tasks are at the moment:

A2: Spatial distribution of magnetic particles inside metamaterials and development of PtP devices.
A3, A7: Temperature-dependent changes of the microstructure, e.g. of TiNi substrates.
A5: Measurements of mechanical deformations provided to A5.
A8: Model for strain in magnetostrictive thin layers.
Z1: Interrelation of piezoelectric performance, microstructure, and chemical composition of AlScN materials.

The major goal of these experiments is to understand the role that structure and stress play in sensor performance from the atomic scale to grain size to microscopic sample size. By understanding these key parameters via XRD and TEM studies, we can work towards knowledge-based sensor design. In addition, we aim to develop micro and nanostructure analysis by achieving a united approach of these powerful structural determination methods.

Project A6 will participate in the focus group F1 “Modeling” and in the focus group F2 “Sensor Concepts”, where the nanostructural aspects of the sensors and their components provide essential information to the project partners.

Project-related Publications

P. Jordt, N. Wolff, S.B. Hrkac, S. Shree, D. Wang, R.J. Harder, C. Kübel, R. Adelung, O.G. Shpyrko, O.M. Magnussen, L. Kienle, B.M. Murphy, Visualizing Intrinsic 3D-Strain Distribution in Gold Coated ZnO Microstructures by Bragg Coherent X-Ray Diffraction Imaging and Transmission Electron Microscopy with Respect to Piezotronic Applications, Advanced Electronic Materials. n/a (n.d.) 2100546.

P. Jordt, S.B. Hrkac, J. Gröttrup, A. Davydok, C. Krywka, N. Wolff, L. Kienle, R. Adelung, O.M. Magnussen, B.M. Murphy, Local Strain Distribution in ZnO Microstructures Visualized with Scanning Nano X-Ray Diffraction and Impact on Electrical Properties, Advanced Engineering Materials. n/a (n.d.) 2100201.

Md.R. Islam, N. Wolff, M. Yassine, G. Schönweger, B. Christian, H. Kohlstedt, O. Ambacher, F. Lofink, L. Kienle, S. Fichtner, On the exceptional temperature stability of ferroelectric Al1-xScxN thin films, Appl. Phys. Lett. 118 (2021) 232905.

N. Wolff, P. Jordt, J. Jetter, H. Vogt, A. Lotnyk, K. Seemann, S. Ulrich, E. Quandt, B.M. Murphy, L. Kienle, Nanostabilization of tetragonal distorted FeCo variants in ultra-thin FeCo/TiN multilayer films, Materials Characterization. 172 (2021) 110871.

N. Wolff, S. Fichtner, B. Haas, M.R. Islam, F. Niekiel, M. Kessel, O. Ambacher, C. Koch, B. Wagner, F. Lofink, L. Kienle, Atomic scale confirmation of ferroelectric polarization inversion in wurtzite-type AlScN, Journal of Applied Physics. 129 (2021) 034103.

U. Schürmann, C. Chluba, N. Wolff, D. Smazna, R. Lima de Miranda, P. Junker, R. Adelung, E. Quandt, L. Kienle, Functional NiTi grids for in situ straining in the TEM. Ultramicroscopy, Vol. 182, pp. 10-16 (2017).

S. B. Hrkac, C. T. Koops, M. Abes, C. Krywka, M. Müller, M. Burghammer, M. Sztucki, T. Dane, Kaps, Y. K. Mishra,R. Adelung, J. Schmalz, M. Gerken, E. Lage, C. Kirchhof, E. Quandt, O. M. Magnussen, B. M. Murphy, Tunable Strain in Magnetoelectric ZnO Microrod Composite Interfaces. ACS Appl. Mater. Interfaces, 9 (30), pp 25571–25577 (2017). DOI: 10.1021/acsami.6b15598

D. Smazna, N. Wolff, S. Shree, F. Schütt, Y.K. Mishra, L- Kienle, R. Adelung, Enhancing the conductivity of ZnO micro- and nanowire networks with gallium oxide. IEEE 7th International Conference Nanomaterials: Application & Properties (NAP), Odessa, pp. 01FNC07-1-01FNC07-5 (2017). doi: 10.1109/NAP.2017.8190199

S. Fichtner, N. Wolff, G. Krishnamurthy, A. Petraru, S. Bohse, F. Lofink, S. Chemnitz, H. Kohlstedt, L. Kienle, B. Wagner, Identifying and overcoming the interface originating c-axis instability in highly Sc enhanced AlN for piezoelectric micro-electromechanical systems. Journal of Applied Physics 122, 035301 (2017). 

S. Kaps, S. Bhowmick, J. Gröttrup, V. Hrkac, D. Stauffer, H. Guo, O. L. Warren, J. Adam, L. Kienle, A. M. Minor, R. Adelung, Y. K. Mishra, Piezoresistive Response of Quasi-One-Dimensional ZnO Nanowires Using an in Situ Electromechanical Device. Acs Omega, 2(6), 2985-2993 (2017). 

E. Yarar, S. Salzer, V. Hrkac, A. Piorra, M. Höft, R. Knöchel, L. Kienle, E. Quandt, Inverse Bilayer Magnetoelectric Thin Film Sensor. Appl. Phys. Lett. 109, 022901 (2016).

E. Yarar, V. Hrkac, C. Zamponi, A. Piorra, L. Kienle, E. Quandt, Low Temperature Aluminum Nitride Thin Films for Sensory Applications, AIP Advances, 6, 075115 (2016).

M. Abes, C. T. Koops, S. B. Hrkac, J. McCord, N. O. Urs, N. Wolff, L. Kienle, W. J. Ren, L. Bouchenoire, B. M. Murphy, O. M. Magnussen, Domain Structure and Reorientation in CoFe2O4. Phys. Rev. B 93, 195427 (2016)

SFB1261 Microsite

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Recent Publications

A. Kittmann, C. Müller, P. Durdaut, L. Thormählen, V. Schell, F. Niekiel, F. Lofink, D. Meyners, R. Knöchel, M. Höft, J. McCord, E. Quandt, Sensitivity and Noise Analysis of SAW Magnetic Field Sensors with varied Magnetostrictive Layer Thicknesses., Sens. Actuators A, 311, 111998 (2020). doi:

N. Lukat, R.-M. Friedrich, B. Spetzler, C. Kirchhof, C. Arndt, L. Thormälen, F. Faupel, C. Selhuber-Unkel, Mapping of magnetic nanoparticles and cells using thin film magnetoelectric sensors based on the delta-E effect Sens. Actuators A, 309. 112023, (2020),

A. Galka, S. Monntaha, M. Siniatchkin, Constrained Expectation Maximisation Algorithm for Estimating ARMA models in State Space Representation, EURASIP Journal on Advances in Signal Processing, Springer Nature, accepted (March 2020).




Prof. Dr. Gerhard Schmidt

Kiel University
Institute for Electrical Engineering and Information Engineering


Internal server



Christian-Albrechts-Universität zu Kiel (CAU)

Christ.-Albrechts-Platz 4
D-24118 Kiel


University Hospital Schleswig-Holstein, Campus Kiel (UKSH)

Arnold-Heller-Straße 3
D-24105 Kiel


Fraunhofer Institute for Silicon Technology, Itzehoe (ISIT)

Fraunhoferstrasse 1
D-25524 Itzehoe  


IPN - Leibniz-Institut für die Pädagogik der Naturwissenschaften und Mathematik 

Olshausenstraße 62 
D-24118 Kiel

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