Staff

Dr. Simon Sawatzki is a postdoctoral researcher in the group of Prof. Gutfleisch. His main expertise is on the processing and characterization of Nd-Fe-B permanent magnets, especially, the hot-deformation and the grain boundary diffusion. More specifically he is an expert in in alloying, powder processing, annealing, densification and deformation of permanent magnets as well as in several characterization methods, e.g. structural (XRD), microstructural (SEM, EDX, TEM), magnetic (VSM, Kerr-Microscopy, SQUID-Magnetometer, Permagraph, Pulsmagnetometer), chemical (ICP-OES, hot-extraction), electrical (4-point-resistivity), and thermal (DSC) characterization. Within his diploma study “Economics and Engineering” at the TU Dresden, which was focused on semiconductor technology, solar technology and energy economics, he also worked practically in the field of thin film technology at the IFW Dresden during his diploma thesis, where he used pulsed laser deposition for depositing exchange coupled SmCo5/Fe multilayers. Current activities at TU Darmstadt are within the LOEWE-Schwerpunkt RESPONSE (Ressourcenschonende Permanentmagnete durch optimierte Nutzung Seltener Erden).

Publications

PhD-Thesis

[1] Der Korngrenzendiffusionsprozess in nanokristallinen Nd-Fe-B-Permanentmagneten. Technische Universität Darmstadt, Darmstadt, PhD. Thesis, (2015) http://tuprints.ulb.tu-darmstadt.de/5221]

Articles

2017

[17] T. Helbig, K. Loewe, S. Sawatzki, M. Yi, B.-X. Xu, O. Gutfleisch, Experimental and Computational Analysis of Magnetization Reversal in (Nd,Dy)-Fe-B Core Shell Sintered Magnets, Acta Mater (2017) (accepted)

[16] S. Muralidhar, J. Gräfe, Y.-Ch. Chen, M. Etter, G. Gregori, S. Ener, S. Sawatzki, K. Hono, O. Gutfleisch, H. Kronmüller, G. Schütz, and E.J. Goering, Temperature-dependent first-order reversal curve measurements on unusually hard magnetic low-temperature phase of MnBi, Phy. Rev. B 95 (2017) 024413 [http://dx.doi.org/10.1103/PhysRevB.95.024413]

2016

[15] Y-Ch. Chen, S. Sawatzki, S. Ener, H. Sepehri-Amin, A. Leineweber, G. Gregori, F. Qu, S. Muralidhar, T. Ohkubo, K. Hono, O. Gutfleisch, H. Kronmüller, G. Schütz, and E.J. Goering, On the synthesis and microstructure analysis of high performance MnBi, AIP Advances 6 (2016) 125201 [http://dx.doi.org/10.1063/1.4971759]

[14] S. Sawatzki, Chr. Kübel, S. Ener, and O. Gutfleisch, Grain boundary diffusion in nanocrystalline Nd-Fe-B permanent magnets with low-melting eutectics, Acta. Mater. 115 (2016) 354-363 [http://dx.doi.org/10.1016/j.actamat.2016.05.048]

2015

[13] S. Sawatzki, T.G. Woodcock, K. Güth, K.-H. Müller, and O. Gutfleisch, Calculation of remanence and degree of texture from EBSD orientation histograms and XRD rocking curves in Nd-Fe-B sintered magnets, J. Magn. Magn. Mater. 382 (2015) 219-224. [http://dx.doi.org/10.1016/j.jmmm.2015.01.046]

[12] R. Sueptitz, S. Sawatzki, M. Moore, M. Uhlemann, O. Gutfleisch, and A. Gebert, Effect of DyF3 on the corrosion behavior of hot-pressed Nd-Fe-B permanent magnets, Mater. Corros. 66, No. 2 (2015) 152-157. [http://dx.doi.org/10.1002/maco.201307303]

2014

[11] S. Sawatzki, S. Ener, Chr. Kübel, and O. Gutfleisch, Effect of DyCu doping of hot-compacted and die-upset Nd-Fe-B magnets, REPM Proc. 23rd Int. Workshop on RE and Future Permanent Magnets and their Applications (Annapolis, USA)(2014) 335-338.

[10] T.G. Woodcock, F. Bittner, T. Mix, K.-H. Müller, S. Sawatzki, and O. Gutfleisch, On the reversible and fully repeatable increase in coercive field of sintered Nd–Fe–B magnets following post sinter annealing, J. Magn. Magn. Mater. 360 (2014) 157-164. [http://dx.doi.org/ 10.1016/j.jmmm.2014.02.025]

[9] S. Sawatzki, I. Dirba, H. Wendrock, L. Schultz, and O. Gutfleisch, Diffusion processes in hot-deformed Nd-Fe-B magnets with DyF3 additions, J. Magn. Magn. Mater. 358-359 (2014), 163-169. [http://dx.doi.org/10.1016/jmmm.2014.01.055]

[8] S. Sawatzki, A. Dirks, B. Frincu, K. Löwe, and O. Gutfleisch, Coercivity enhancement in hot-pressed Nd-Fe-B permanent magnets with low melting eutectics, J. Appl. Phys. 115 (2014) 17A705. [http://dx.doi.org/10.1063/1.4859097]

[7] I. Dirba, S. Sawatzki, and O. Gutfleisch, Net-shape and crack-free production of Nd-Fe-B magnets by hot deformation, J. Alloy. Compd. 589 (2014) 301-306. [http://dx.doi.org/10.1016/j.jallcom.2013.11.188]

2013

[6] S. Sawatzki, I. Dirba, L. Schultz, and O. Gutfleisch, Electrical and magnetic properties of hot-deformed Nd-Fe-B magnets with different DyF3 additions, J. Appl. Phys. 114, (2013) 133902. [http://dx.doi.org/10.1063/1.4822026]

2012

[5] S. Sawatzki, M. Moore, H. Wendrock, L. Schultz, and O. Gutfleisch, Thermal stability of hot-pressed NdFeB magnets with Dy-fluoride additions, REPM Proc. 22nd Int. Workshop on RE Permanent Magnets and their Applications (Nagasaki, Japan)(2012) 409-412.

[4] V. Neu, S. Zimmermannn, S. Sawatzki, I. Mönch, and L. Schultz, Imaging the magnetization processes in epitaxial exchange coupled SmCo5/Fe/SmCo5 trilayers, IEEE Trans. Magnetics 48 (2012) 3644 – 3647 [http://dx.doi.org/10.1109/TMAG.2012.2195299]

[3] V. Neu, S. Sawatzki, M. Kopte, Ch. Mickel, and L. Schultz, Fully epitaxial, exchange coupled SmCo5 / Fe / SmCo5 multilayers with energy densities above 400 kJ/m3, IEEE Trans. Magnetics 48 (2012) 3599 – 3602. [http://dx.doi.org/10.1109/TMAG.2012.2195646]

2011

[2] M. Kopte, S. Sawatzki, L. Schultz, and V. Neu, The Nucleation of the Spin Spiral in Epitaxial SmCo5 / Fe / SmCo5 Exchange Spring Trilayers, IEEE Trans. Magnetics 47 (2011) 3736 – 3739. [http://dx.doi.org/10.1109/TMAG.2011.2154303]

[1] S. Sawatzki, R. Heller, Ch. Mickel, M. Seifert, L. Schultz, and V. Neu, Largely enhanced energy density in epitaxial SmCo 5 /Fe/SmCo 5 exchange spring trilayers, J. Appl. Phys. 109 (2011) 123922. [http://dx.doi.org/10.1063/1.3596756]

Invited Talks and Awards

04/2015 Invited Talk, 3. Workshop Materialien für die Energiewende: Magnetwerkstoffe, Dresden

„Stand der Forschung auf dem Gebiet der hartmagnetischen Materialien“

09/2012 Best Poster Award, REPM, Nagasaki, Japan

“Thermal Stability of Hot-Pressed NdFeB Magnets with Dy-Fluoride Additions”

11/2011 Invited Talk, FVA Infotagung, Würzburg

„Hochleistungspermanentmagnete für die Anwendung in leistungsstarken Elektromotoren“