Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 16: Magnetic Particles / Clusters II

MA 16.5: Vortrag

Dienstag, 27. März 2012, 10:30–10:45, EB 202

GMR-effects in jelly-like structures — •Judith Meyer, Markus Schäfers, and Andreas Hütten — Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany

The GMR-effect was found and originally studied in magnetic multilayer systems [1,2]. In 1992, it was also independently reported within granular systems by several research groups who had embedded magnetic particles in a metallic matrix [3,4]. In contrast to previous granular layered systems prepared by the use of sputtering or metallurgical procedures, we have chosen a nonmagnetic conductive water-based gel as carrier substance for the magnetic nanoparticles. By doing so, GMR effects of up to several hundred percent have been measured for both Co- and Heusler based nanoparticles. By choosing gel matrices conductivity and hence the GMR-effect amplitude can be adjusted. Regarding future applications, the possibility of printing gel would allow the realization of a granular GMR sensor without employing photo- or e-beam lithography.

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[2] M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen Van Dau, F. Petroff, Phys. Rev. Lett. 61, 2472 (1988)

[3] A. E. Berkowitz, J. R. Mitchell, M. J. Carey, A. P. Young, S. Zhang, F. E. Spada, F. T. Parker, A. Hütten, G. Thomas, Phys. Rev. Lett., 68, 3745 (1992)

[4] J. Q. Xiao, J. S. Jiang, C. L. Chien, Phys. Rev. Lett., 68, 3749 (1992)