Herstellung und Charakterisierung eines Spinventils zur Untersuchung der Spindiffusionslänge von FeAl

Spintronic devices hold great potential for future applilcations in information technology. In this work, the design and fabrication of a lateral spin valve for investigating the spin diffusion length of paramagnetic Fe60Al40 will be discussed. Samples were prepared by defining polycrystalline circuits using electron beam lithography, thin film deposition, and lift-off processing. The developed sample layout allows for both local and non-local measurement routines. Cobalt was employed as ferromagnetic polarizing material, while aluminium holds for reference measurements of the spin diffusion length. The determination of the so far unknown spin diffusion length of paramagnetic Fe60Al40 shall then be performed by detecting resistance changes at different temperatures and for different polarizer distances. Highly sensitive electric transport measurements were carried out in a so-called probe station, which allows for achieving very low temperatures via liquid He cooling. Additionally, paramagnetic ferromagnetic heterostructures were investigated with respect to possible giant magneto resistance effects.