MAGNETORESISTANCE AND SPIN-FILTERING EFFICIENCY OF DNA-SANDWICHED FERROMAGNETIC NANOSTRUCTURES

We report magnetoresistance and spin-filtering efficiency of DNA-sandwiched ferromagnetic nanostructures. Commercially available FeCo target was sputtered over a gold-coated silicon wafer coated with mercaptosuccinic acid and DNA. This was made to contact with another FeCo sputtered gold-coated silicon wafer coated with mercaptosuccinic acid forming FM/DNA/FM based magnetic junction. DNA forms a covalent bonding with FeCo nanoparticles through mercaptosuccinic acid. Magnetoresistance for this was measured in the room temperature and was found to be 18%. Spin-filtering efficiency was calculated as 30%, which is half the value of experimental observation of spin-filtering of electron on pure gold surface coated with DNA.