# Corrélations entre hétérogénéités magnétiques ettransport électrique dans des nanostructures

Abstract : The aim of this thesis is to understand the influence of magnetic heterogeneitie
s on the electric transport properties in nanostructures. For this purpose, we d
eveloped a Magnetic Force Microscope working under a variable magnetic field up
to 2T. We were also able to measure in real time the transport properties in ord
er to correlate them with MFM imaging.
The study of an hybrid metal/insulator structure (a garnet/nickel bilayer) allow
s us to characterize the coupling at the interface between a ferri- and a ferro-
magnet. We evidence the rigidity, on a 10$\mu$m length scale, of the garnet doma
ins structure by coupled MFM+transport measurements.
We also study the current-induced domain wall motion effect both theoretically a
nd experimentally. We developed a classical model to account for the spin transf
er effect from a polarised current along with a new mechanism based on electric
charging of the wall due to the Hall effect. Our experimental studies on current
injection in ultra-thin cobalt layers with high perpendicular anisotropy show t
hat domain wall depinning is the dominant effect in this system. This result is
explained by the wall structure distortion induced by the current.
Keywords :
Document type :
Theses

Cited literature [59 references]

https://tel.archives-ouvertes.fr/tel-00121862
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Submitted on : Friday, December 22, 2006 - 12:31:56 PM
Last modification on : Wednesday, December 9, 2020 - 3:16:46 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 7:37:00 PM

### Identifiers

• HAL Id : tel-00121862, version 1

### Citation

Antoine Vanhaverbeke. Corrélations entre hétérogénéités magnétiques et
transport électrique dans des nanostructures. Matière Condensée [cond-mat]. Université Pierre et Marie Curie - Paris VI, 2005. Français. ⟨tel-00121862⟩

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