| Popis: |
We present experimental research on magneto-transport on micro and nanostructures based on the ferromagnetic semiconductor (Ga,Mn)As, as well as macroscopic (un-patterned) samples. We report the values of contact resistance measurements between (Ga,Mn)As with different materials; copper, silver and aluminum. Copper gave relatively high values of contact resistance whereas aluminum gave extremely high values. Our values for specific resistance for silver of ~10-8 Ωcm2 are very low and agree with literature. We also report a process for the fabrication of the non local spin valves (NLSV’s) using electron beam lithography. Finally we present our studies of the effect of native and grown oxides on the Curie temperature and resistivity of (Ga,Mn)As. Our results show that etching the oxide and annealing at temperatures close to growth temperatures enhances the Curie temperature and reduces the resistivity of the samples. The repeated anneal etch process improves the Curie temperature fast compared to continuous annealing. |
