Growth of half-metallic Co₂FeSi thin films on silicon (0 0 1) substrate by dc magnetron sputtering

Co₂FeSi thin films were deposited on Si (0 0 1) substrate by dc magnetron sputtering technique by varying the sputtering pressure and power. In all cases but one, the substrate temperature was kept at room temperature during deposition. In one case the deposition was carried out at a substrate temperature of 773 K. All the films were post-deposition annealed at 773 K. The composition, surface roughness, structure, magnetic properties and electrical resistivity of these films were examined to identify the suitability of these films for spintronic applications. The results showed that Co₂FeSi thin films deposited at 3 mTorr sputtering pressure and 100 W sputtering power at a substrate temperature of 773 K and subsequently annealed at the same temperature for 30 min exhibited the same stoichiometry as the target, low surface roughness, L2₁ ordering as well as good magnetic properties. The variation of electrical resistivity with temperature and the sign crossover in the anisotrpoic magnetoresistance behavior in this film suggested the presence of half-metallic character and suitability for spintronic applications