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Room temperature paramagnetism of ZnO:Mn films grown by RF-sputtering
Oliveira, Filipe André; Cerqueira, M. F.; Vasilevskiy, Mikhail; Viseu, T. M. R.; Campos, J. Ayres de; Rolo, Anabela G.; Martins, J. S.; Sobolev, N. A.ZnO:Mn transparent thin films (thickness b1 μm) with the Mn contents ranging from 1.8 to 3.25 at.% were grown by RF magnetron co-sputtering. The films are nanocrystalline, with wurtzite-structure grains of a typical size of 20 nm and with a preferential orientation of the c-axis perpendicular to the surface. According to the Raman spectroscopy data, Mn mostly substitutes Zn in the lattice sites. In spite of the...
Structural and optical properties of Zn0.9 Mn0.1 O/ZnO core-shell nanowires des...
Kaydashev, V.E.; Kaidashev, E.M.; Peres, M.; Monteiro, T.; Correia, M.R.; Sobolev, N.A.; Alves, L.C.; Franco, N.; Alves, E.Core-shell ZnO/ZnMnO nanowires on a-Al2O3 and GaN (buffer layer)/Si (111) substrates were fabricated by pulsed laser deposition using a Au catalyst. Two ZnO targets with a Mn content of 10% were sintered at 1150 and 550 °C in order to achieve the domination in them of paramagnetic MnO2 and ferromagnetic Mn2O3 phases, respectively. Cluster mechanism of laser ablation as a source of possible incorporation of seco...
Surface modification of Co-doped ZnO nanocrystals and its effects on the magnet...
Pereira, A. S.; Ankiewicz, A. O.; Gehlhoff, W.; Hoffmann, A.; Pereira, S.; Trindade, T.; Grundmann, M.; Carmo, M. C.; Sobolev, N. A.A series of chemically prepared Co2+-doped ZnO colloids has been surface modified either by growing shells of ZnSe or by the in situ encapsulation in poly styrene . The surface modification effects using these two distinct chemical strategies on the magnetic properties of the nanocrystals were probed by electron paramagnetic resonance EPR . Structural characterization by means of x-ray diffraction and transmis...
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