Magnetoresistive Devices: Magnetic Memory, Magnetic Logic and Magnetic Sensors

Günter Reiss

Scope of CSMD

Research in spinelectronics recently has produced amazing results on new physical effects such as the field-free switching of the magnetization by spin currents, the discovery of new ferromagnetic materials with 100% spin polarization at the Fermi level, their integration in Magnetic Tunnel Junctions (MTJs), new spin dependent thermoelectric effects, memristive behavior of tunnel junctions and even a new material class for topological insulators. In particular, new materials such as Heusler alloys have a substantial share of this progress in science. Many groups worldwide have an urgent need for high quality samples in order to further develop the materials and/or characterization techniques. There are, however, only a small number of teams scattered around the world capable of providing such bulk-, thin film- or device-samples.
CSMD has been funded from July 2013 through June 2015 by the Ministerium für Innovation, Wissenschaft und Forschung of North Rhine-Westphalia to initiate a highly competitive and complete plattform of expertise and technology in this field. External research groups of academia and industry interested in driving spinelectronics forward and creating new products can be supplied with consulting as well as with custom-designed samples of new materials such as Heusler alloys and devices such as magnetic tunnel junctions.

Offers of CSMD

Materials and Thin Films
In particular, new ternary and quaternary materials from the Heusler family can be prepared and characterized. For the development of new materials rational design by computer simulations (DFT) is employed to screen for anticipated properties such as spin polarisation, magnetisation, anisotropy or magnetic damping. With state-of-the-art thin film deposition and analysis tools ranging from sputter- via e-beam- to MBE-deposition advanced thin film systems can be prepared, characterised and supplied to interested groups to experimentally verify the theoretical material screening.
The technological plattform includes an industrially relevant system for preparation of thin film systems on large substrates.

For experiments on devices, the center provides the integration of newly developed thin film materials in magnetic tunnel junctions (MTJs) which can be patterned down to a size below 100nm by e-beam lithography. The center supplies layout proposals to interested researchers and subsequently customized samples for experiments on, e.g., dynamics or transport. Samples can be pre-characterized in CSMD by, e.g., structural and static transport measurements.

The Center is open for contributing to the development of industrially relevant prototypes for a variety of application fields:
* Non volatile Random Access Memories based on Spin Transfer Torque
* Related and field programmable magnetic logic gates
* Magnetic Sensors with high sensitivity to detect ultrasmall magnetic fields
* Sensor arrays for magnetic cameras to scan information in, e.g., security systems for product control
* Sensors for magnetoresistive Biochips capable to detect small concentrations of, e.g., antibodies, DNA sequences or proteins.


The Center supplies both support in the development as well as samples to research groups or companies interested in developing and/or using state-of-the-art spinelectronic materials and (prototype) devices.
The collaboration can be organized in direct contracts or within funded projects.
Interested? Use the contact form on this page or send an e-mail to:
Jun.-Prof. Dr. Markus Meinert (CEO,
Prof. Dr. Günter Reiss (

Selected Publications

D. Meier, D. Reinhardt, M. van Straaten, C. Klewe, M. Althammer, M. Schreier, S.T.B. Goennenwein, A. Gupta, M. Schmid, C.H. Back, J.-M. Schmalhorst, T. Kuschel, G. Reiss: Longitudinal spin Seebeck effect contribution in transverse spin Seebeck effect experiments in Pt/YIG and Pt/NFO, Nature Communications 6, 9211 (2015)

T. Kuschel, C. Klewe, J.-M. Schmalhorst, F. Bertram, O. Kuschel, T. Schemme, J. Wollschläger, S. Francoual, J. Strempfer, A. Gupta, M. Meinert, G. Götz, D. Meier, G. Reiss: Static proximity effect in Pt/NiFe2O4 and Pt/Fe bilayers investigated by x-ray resonant magnetic reflectivity, Physical Review Letters 115, 097401 (2015)

A. Tavassolizadeh, T. Meier, K. Rott, G. Reiss, E. Quandt, H. Holscher, D. Meyners, Self-sensing atomic force microscopy cantilevers based on tunnel magnetoresistance sensors, Appl. Phys. Lett, 102 (2013) 153104

R. Weiss, R. Mattheis, G. Reiss, Advanced giant magnetoresistance technology for measurement applications, Measurement Science and Technol., 24 (2013) 082001

M. Walter, J. Walowski, V. Zbarsky, M. Münzenberg, M. Schäfers, D. Ebke, G. Reiss, A. Thomas, P. Peretzki, M. Seibt, J.S. Moodera, M. Czerner, M. Bachmann, C. Heiliger, Seebeck Effect in magnetic tunnel junctions, Nature Materials, 10 (2011) 742

G. M. Müller, J. Walowski, M. Djordjevic, G.-X. Miao, A. Gupta, A. V. Ramos, K. Gehrke, V. Moshnyaga, K. Samwer, J. Schmalhorst, A. Thomas, G. Reiss, J. S. Moodera, M. Münzenberg, Spin Polarization in Half Metals Probed by Femtosecond Spin Excitation, Nature Materials, 8 (2009) 56

G. Reiss, J. Schmalhorst, A. Thomas, A. Hütten, S. Yuasa: 'Magnetic Tunnel Junctions', Springer Tracts in Modern Physics 227 (2008) 291 - 333

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