TY  - THES
AB  - The basic element for innovative sensors and memory devices is the magnetic tunnel junction. It consists of two ferromagnetic layers. These are separated by a thin insulating alumina layer. The resistance of the insulator (the tunneling barrier) depends on the relative orientation of the magnetization of the adjacent ferromagnetic layers. The change in resistance is called tunneling magnetoresistance (TMR) effect. In a simple approximation the TMR effect depends on the spin polarization of the ferromagnetic layers. Using half-metals - these are fully spin polarized - one can theoretically expect an infinite TMR effect.
The preparation of junctions (this includes the deposition of the layers, oxidation of an aluminum layer to the insulating alumina barrier and tempering of the stack) with ideal layers and interfaces is often impossible. Thus, in actual tunnel junctions the TMR effect scales with the quality of the electrodes, the barrier and the interface between these layers.
This thesis deals with the optimization of tunnel junctions with half-metallic electrodes, e.g. the ferromagnetic oxide magnetite (Fe3O4) and the Heusler alloys Co2MnSi and Co2FeSi. The main topic is a systematic characterization of the magnetic, chemical and electronic structure of the interface between electrode and insulator.
DA  - 2007
KW  - Magnetisches Tunnelelement , Heuslersche Legierung , Magnetoelektronik , Tunnelmagnetowiderstand , Halbmetall , MRAM , Bandstruktur , Co2MnSi , Co2FeSi , Fe3O4 , TMR , Al2O3 ,
LA  - ger
PY  - 2007
TI  - Charakterisierung der Barrieren-Grenzflächen magnetischer Tunnelelemente mit halbmetallischen Elektroden
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:361-11757
Y2  - 2024-11-22T04:40:35
ER  -