Magnetic and electrical characterization of TiO2 single crystals co-implanted with iron and cobalt

• Published in: Journal of magnetism and magnetic materials 2014-09, Vol.364, p.106-116
• Main Authors: Silva, C., Costa, A.R.G., da Silva, R.C., Alves, L.C., Ferreira, L.P., Carvalho, M.D., Franco, N., Godinho, M., Cruz, M.M.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Diamagnetism, paramagnetism and superparamagnetism; Diluted magnetic semiconductor; Electronic transport in condensed matter; Exact sciences and technology; Galvanomagnetic and other magnetotransport effects; Implanted rutile; Magnetic nano-aggregate; Magnetic properties and materials; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Magnetoresistance; Mössbauer effect; other γ-ray spectroscopy; Physics
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2014.04.022

Single-crystals of TiO2 rutile were co-implanted with iron and cobalt to investigate the combined role of these ions in the magnetic properties of the system. The implantations were carried out using an energy of 150keV and different fluences to investigate their influence in the magnetic and electrical properties of the implanted samples. For the higher fluences the as implanted single crystals exhibit superparamagnetic behaviour associated with the formation of nanosized magnetic aggregates. Annealing treatments were performed at 673K and 1073K, inducing recovery of the lattice structure and the evolution of the formed phases. Iron and cobalt play different roles in the implanted region, the presence of iron inhibiting the formation of cobalt aggregates during annealing at 1073K. •Co-implantation of Fe/Co into rutile leads to the formation of magnetic nanoparticles.•The sizes of the magnetic nano-aggregates depend on the implanted fluence.•The system displays negative magneto resistance associated with magnetic aggregates.•Fe dominates the HT annealed samples behavior, inhibiting Co aggregate formation.