Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)

MA 32.17: Poster

Freitag, 29. Februar 2008, 11:15–14:00, Poster E

Magnetoresistive effects in ultrathin magnetic films — •Stephen Krzyk, Alexander von Schmidsfeld, Mathias Kläui, and Ulrich Rüdiger — Fachbereich Physik, Universität Konstanz, 78457 Konstanz

Inspired by the successful industrial application of the giant magnetoresistance effect (GMR), magnetoresistance properties of nanoscale structures are the subject of intense research. Recent experiments [1] have shown that decreasing the cross section of a nanocontact leads to a significantly increased magnitude of the anisotropic magnetoresistance.

A possible approach to small contact sizes are ultrathin films near the percolation threshold. We investigate magnetotransport through permalloy (Ni₈₀Fe₂₀) and iron films grown on isolating substrates such as MgO. Deposition of films in the monolayer range was carried out in an MBE chamber designed for in situ magnetoresistance measurement during film growth. Magnetic fields of up to 100 mT can be applied in the sample plane, and the resistances between fixed sample locations can be measured during growth. The field angle and strength is varied for the purpose of distinguishing between TMR and AMR effects. The measurements can be carried out by increasing the thickness with sub-monolayer resolution.

[1] K. I. Bolotin et al., Phys. Rev. Lett. 97, 127202 (2006)