Skip to Main content Skip to Navigation
Theses

Spintronics with alternative materials: full-Heusler alloys and diluted magnetic oxides

Abstract : The polarization of the spin current in a spintronic device is at the origin of magneto-resistive effects that define its functional properties. Typically, in order to spin-polarize a current of electrons two alternatives are used: the electron current crosses either a ferromagnetic metal or a magnetic oxide barrier. Within this thesis, we addressed both alternatives. In a first step, layers of TiO2 diluted magnetic oxide type doped with cobalt were prepared by sputtering. Their structural, morphological and magnetic properties were studied to optimize their potential for integration into a complex spin filter type structure. In a second step, we focused our efforts on the elaboration and the study of single-crystal magnetic tunnel junction based on the full-Heusler alloy Co2FeAl and the MgO (001) tunnel barrier. From a theoretical point of view, the Heusler alloys are expected to be half-metallic. This leads to a spin polarization of 100%. Following a parallel crystallographic and magnetic study of thin Co2FeAl alloy films, we demonstrated a direct correlation between structural and magnetic anisotropies. Using these layers as magnetic electrodes, we elaborated and studied UV micro-structured crystalline magnetic tunnel junctions. Our analysis demonstrates that the spin polarized tunneling and the quality of the half-metallicity of the alloy has a clear dependence on the degree of crystallinity of the system. Beyond the purely experimental aspects, this thesis includes studies of analytical, numerical and ab-initio modeling of the magnetic and electronic properties as well as for the spin polarized transport in the studied systems and devices
Complete list of metadata

Cited literature [171 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01746191
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 10:26:44 AM
Last modification on : Thursday, February 25, 2021 - 11:04:17 AM
Long-term archiving on: : Thursday, September 13, 2018 - 11:40:06 AM

File

SCD_T_2011_0040_GABOR.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01746191, version 1

Citation

Mihai Sebastian Gabor. Spintronics with alternative materials: full-Heusler alloys and diluted magnetic oxides. Other [cond-mat.other]. Université Henri Poincaré - Nancy 1, 2011. English. ⟨NNT : 2011NAN10040⟩. ⟨tel-01746191⟩

Share

Metrics

Record views

212

Files downloads

1052