Regensburg 2010 – scientific programme

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MA: Fachverband Magnetismus

MA 33: Poster II

MA 33.32: Poster

Friday, March 26, 2010, 11:00–14:00, Poster B1

The influence of size and aspect ratio on the switching properties of elliptical elements: an OOMMF Approach — •Andres Conca Parra, Ana Ruiz Calaforra, Britta Leven, and Burkard Hillebrands — FB Physik and Landesforschungszentrum OPTIMAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany

The understanding and control of the switching properties in TMR elements is a critical point for certain applications such as MRAM memories. The magnetization dynamics depends on the size and shape of the element, the interlayer coupling in the TMR stack as well as the duration and amplitude of the magnetic field pulses used for switching. The elliptical shape is widely used due to the fact that the demagnetizing field induces a homogeneously magnetized state in remanence. However, depending on the thickness and the aspect ratio of the ellipse, the magnetic elements may show a domain structure in remanence or after excitation with magnetic field pulses.

We performed micromagnetic simulations for elliptical elements with different dimensions using the open code OOMMF. The simulations were performed for application relevant materials such as NiFe, CoFe and CoFeB. The magnetization state in remanence as well as the reaction of the elements to excitation with pulses with different amplitudes and duration were simulated. A comparison between elements and the most suitable strategy for a fast and reliable operation is discussed.

Support by the BMBF project MultiMag (VDI-TZ 13N9913) is acknowledged.