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MA: Magnetismus

MA 17: Spinabh
ängiger Transport II

MA 17.4: Talk

Monday, March 7, 2005, 11:15–11:30, TU H1012

Collective spin fluctuations in Fe and Fe₃Si films on GaAs substrates — •K. - J. Friedland, M. Bowen, J. Herfort, P. K. Muduli, H. P. Schönherr, and K. H. Ploog — Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany

The planar Hall effect is a powerful tool to study the magnetization and its reversal in ferromagnetic layers as a function of the external magnetic field. Complementary to other methods such as superconducting quantum interference device magnetometry, magnetotransport measurements can extract magnetization information from small volumes and even low-dimensional structures, demonstrating the importance of magnetotransport measurements for spintronics. In addition, a detailed investigation of related transport phenomena can give insight into the spin texture and the ordering of magnetic substructures. Using Fe and in Fe₃Si films grown by molecular-beam epitaxy on GaAs(001) and (113)A substrates, we present experimental evidence for additional contributions to the planar Hall effect due to collective spin fluctuations and the non-trivial spin topology in the lattice with a non-zero Berry phase. Experiments performed on the Heusler alloy Fe_3+xSi_1−x in the range −0.08 < x < 0.06 demonstrate the impact of structural ordering and thermally regulated magnetic ordering on this intrinsic magnetotransport regime.