Cooperative nucleation modes in polycrystalline CoxPd1-x nanowires

Polycrystalline CoxPd1-x (x=1, 0.60, 0.45, 0.23, and 0.11) cylindrical nanowires (ø=18-35nm, about 1μm length) are produced by AC electrodeposition into hexagonally ordered alumina pores. Single-phase nanowires of an fcc Co-Pd solid solution, with randomly oriented equiaxed grains (7-12nm) are obtained; in all the cases, the grain size is smaller than the wire diameter. The coercive field and the reduced remanence of Co-rich nanowire arrays are hardly sensitive to temperature within the range varying from 4K to 300K. On the other hand, in Pd-rich nanowires both magnitudes are smaller and they largely increase when cooling below 100K. This behavior also depends on the mean grain size. These facts are systematized considering two main aspects: the non-trivial temperature and composition dependence of the crystalline anisotropy and the saturation magnetostriction in Co-Pd alloys; and a random anisotropy effect, which defines a nucleation localization length that may involve more than a single grain, and thus promotes more cooperative nucleation modes.Fil: Viqueira, María Soledad. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Pozo Lopez, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Condo, Adriana Maria. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Física de Metales; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Cornejo, Daniel Reinaldo. Universidade de Sao Paulo; BrasilFil: Fabietti, Luis Maria Rodolfo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin

Very low potential electrodeposition of Sm-Co nanostructures in aqueous medium using hard templates

Arrays of SmCo nanowires (NW) and nanotubes (NT) with a diameter of 200 nm and different lengths are synthesized by electrodeposition into the nanopores of an alumina membrane. The potential applied during the synthesis largely determines the nanostructure morphology, its crystallinity and composition. Potentials investigated are between −0.8 V and −3.0 V; in the potential range between −0.8 V and 1.0 V, long and perfectly ordered nanowires are obtained with a composition close to that of the equilibrium Sm2Co17 phase in the binary alloy. For higher potentials, above −1 V, samples are nanotubes, 195 nm in external diameter and wall thickness of 30 nm with an equiatomical composition. Magnetic characterization reveals that all the nanostructures are soft ferromagnetic, with coercivity values below 60 mT. From the angular dependence of coercivity and the relative remanence it may concluded that in both, nanowires and nanotubes the magnetization reversal mechanism undergoes a transition from one at smaller angles, involving localized nucleation by curling, and further expansion of vortex-like domain walls. At higher angles, where the applied field is almost perpendicular to the NW/NT long axis, the mechanism changes to one involving nucleation by localized coherent rotation and further expansion of transverse Bloch-like walls.Fil: Herrera, Elisa Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Riva, Julieta Soledad. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pozo Lopez, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Condo, Adriana Mar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Física (cab). Div.física Teórica; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Fabietti, Luis Maria Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

Magnetic hysteresis in small-grained CoxPd1-x nanowire arrays

Co-Pd nanowires with small grain size are fabricated by AC electrodeposition into hexagonally ordered alumina pores, 20-35 nm in diameter and about 1 μm long. The effects of the alloy composition, the nanowire diameter and the grain size on the hysteresis properties are considered. X-ray diffraction indicates that the nanowires are single phase, a fcc Co-Pd solid solution; electron microscopy results show that they are polycrystalline, with randomly oriented grains (7-12 nm), smaller than the wire diameter. Nanowire arrays are ferromagnetic, with an easy magnetization axis parallel to the nanowire long axis. Both, the coercive field and the loop squareness monotonously increase with the Co content and with the grain size, but no clear correlation with the wire diameter is found. The Co and Co-rich nanowire arrays exhibit coercive fields and reduced remanence values quite insensitive to temperature in the range 4 K-300 K; on the contrary, in Pd-rich nanowires both magnitudes are smaller and they largely increase during cooling below 100 K. These behaviors are systematized by considering the strong dependences displayed by the magneto-crystalline anisotropy and the saturation magnetostriction on composition and temperature. At low temperatures the effective anisotropy value and the domain-wall width to grain size ratio drastically change, promoting less cooperative and harder nucleation modes.Fil: Viqueira, María Soledad. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Pozo Lopez, Gabriela del Valle. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Condo, Adriana Maria. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Cornejo, Daniel Reinaldo. Universidade de Sao Paulo; BrasilFil: Fabietti, Luis Maria Rodolfo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin

Microstructure and magnetic properties of as-cast Ni2MnGa rods and tubes solidified by suction casting

Ni2MnGa cylinders and tubes are solidified in water chilled copper molds, a few millimeters in external diameter and 5 cm long, by the suction casting technique. At room temperature, all samples are in cubic austenitic phase. Microstructure and crystallographic texture of the as-cast rods and tubes are characterized by XRD, SEM, EBSD and TEM. Because of the heat extraction geometry samples exhibit a strong texture, with the [100] direction preferentially oriented in the radial direction, together with a random distribution on the long axis. This texture is more marked in the tubes. XRD and TEM results indicate that the major austenitic phase is fcc, with L21 order. A minority volume of the equilibrium B2′ disordered phase is detected by the presence of two close Curie temperatures in cylinders and tubes 2 mm in external diameter, but not when this diameter is near 1 mm. Precipitates of the stable compounds α-Mn(S,Se), with a NaCl-type structure, and monoclinic P4S5 are observed in all the samples. Cylinders and tubes in austenitic phase are magnetically soft. Hysteresis loops in martensitic phase exhibit local steps associated to a magnetization mechanism involving twin boundary displacement, indicating that a field-induced variant reordering takes place. The switching field Hsw, corresponding to the magnetization step observed, is identified as the field at which twin boundaries become mobile. The measured values of 0.37 T–0.49 T are consistent with those corresponding to the onset of Type I twin boundaries displacement in 5 M martensite, with an equivalent threshold stress of 1 MP.Fil: Pozo Lopez, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Condo, Adriana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Física de Metales; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Limandri, Silvina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Mutal, Ruben Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Winkler, Elin Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Fabietti, Luis Maria Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

Effect of an external magnetic field orthogonal to the electrode surface on the electrocrystallization mechanism of Co-Fe films under pulsed applied potential

Co100−xFex (x = 0; 50; 30; 20) films are prepared by pulse-reverse plating onto Cu foils, in the presence of a magnetic field of 100 mT applied orthogonally to the substrate surface (B100) and in the condition B ~ 0 (B0). Energy-dispersive X-ray spectroscopy studies indicate that the Fe/Co ratios in the films are similar to those in the feed solution. The electrochemical nucleation and growth of Co and Co-Fe films are analyzed for individual, consecutive cathodic pulses, and also considering them as a continuous transient to achieve a steady stationary state. Current-time transient are analyzed applying the generalized Scharifker-Mostany model, assuming that parameters take effective values, describing the non-single-ion diffusion involved. All Co and Co-Fe films exhibit a 3D nucleation regime and diffusion-controlled growth. Films of pure cobalt prepared at B0 exhibit progressive nucleation (3DP) while bimetallic ones an instantaneous regime (3DI) predominates. Current-time transients obtained at B100 undergo changes from 3DI nucleation, for pure Co, turning more progressive 3DP regime for bimetallic, as the iron content increases. Film morphology and microstructure largely depend on Fe/Co composition and the applied magnetic field. For low iron content, films are granular and change to dendritic-like when iron content increases. Besides, for Co70Fe30 and Co50Fe50 compositions, nanowall-like structures at the surface change into whisker-like prisms when the magnetic field is applied. Iron containing films are thinner when deposited at B100 for all compositions. The key factors explaining the influence of the magnetic field and composition on the film deposition mechanisms and microstructure are: micro-magneto-hydrodynamic convection nearby the interface, the H2 desorption and the competence/interplay of Co(II) and Fe(II) ions during the alloy nucleation and growth.Fil: Aguirre, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

A Cu2+-Cu/glassy carbon system for glyphosate determination

Cu° electrocrystallization onto glassy carbon (GC) at potentials between −0.4 V and −0.7 V is consistent with a 3D progressive nucleation mechanism and diffusion-controlled growth. Cu/GC electrode prepared at −0.6 V is applied to the detection of a widely used herbicide such as glyphosate (Glyp). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods are applied in the Glyp determination in acetic acid buffer aqueous solution (ABS) at pH 5 or pH 6. Optimal herbicide detection properties are found for this electrode, arising from Cu°/Cu+ and Cu+/Cu2+ couples. An interesting phenomenon is detected by the DPV method, with Cu/GC electrode in presence of (0.03–0.2 mM) Cu2+ into the ABS at pH 6, when glyphosate is added. For an oxidation potential of −0,015 V vs. Ag/AgCl for Cu°/Cu+ couple (DPV), the current peak is sensitively affected by glyphosate concentration. A strong adsorptive effect between 6 and 30 μM of analyte leads to a linear decrease in the current peak at pH 6. This phenomenon is related to the formation of a barrier of adsorbed glyphosate molecules, which prevent Cu2+ ions diffusion towards the electrode's surface. CVs and DPVs for Cu/GC electrode system in the presence of Glyp and Cu2+ ions are consistent with the transfer of one electron from Cu2+ to Cu+ and from Cu+ to Cu0, which is limited by diffusion of Cu2+ ions. A quantification limit (LOQ) for Glyp of (0.62 ± 0.02) μM [(105 ± 3) μg L–1], and a low determination limit (LOD) of (0.186 ± 0.004) μM (31 (μg L–1) (31g/L)) are obtained from Cu/GC system into ABS pH 6 and 0.1 mM Cu2+ ions. Glyp Determinations for Cu2+-Cu/GC in the presence of interfering cations and in drinking water demonstrated similar sensitivity and stability as in pure systems.Fil: Aguirre, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba; ArgentinaFil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentin

Coating of aluminum substrates with nanostructured Pd–Ni alloys by electrodeposition

Pd–Ni alloys are electrodeposited onto low-purity aluminum substrates varying both the composition of the feeding solution and the applied electrodeposition potential. It is found that the initial nucleation-and-growth mechanism in every case is well described by a 3D-type nucleation process. The resulting deposits consist of Pd–Ni alloys of different compositions, all electrocrystallized in a disordered fcc phase; depending on the electrodeposition parameters, different morphologies and compositions are obtained. It is found that when the electrodeposition potential is high and the Pd content in the feeding solution is low, the substrate coating is more efficient and the deposit morphology tends to refine into dendritic-like structures, making this kind of deposit quite interesting for using as electrodes in electrochemical devices. Room temperature magnetic measurements indicate that the samples are soft ferromagnetic with negligible demagnetizing effects. Dendritic and spheroidal-like Pd-rich deposits exhibit larger remanence values and are more coercive than those with higher Ni content due to the dependence of the anisotropy constant on the alloy composition.Fil: Meneses, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Riva, Julieta Soledad. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Bercoff, Paula Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin

Catalytic properties of Fe–Pd ferromagnetic nanowires at liquid/liquid interfaces

Fe–Pd binary alloy nanowires (NWs) were synthesized by electrodeposition method with the assistance of nanoporous anodic alumina (AAO). We focus on the synthesis conditions of Fe–Pd nanowires and the characterization of the resulting composition, size and morphology, and their magnetic and catalytic properties at liquid/liquid interfaces. A number of factors may affect the formation and properties of nanoparticles during the synthesis. Here, we focused on finding the effect of the applied potential on the resulting NWs. Moreover, it is shown that Fe–Pd NWs catalyse ion transfer across a soft water/1,2-dichloroethane interface, with a lower overpotential to that reported at bare soft interfaces. Furthermore, the NWs’ motion at a liquid/liquid interface is monitored by optical microscopy which allows demonstrating that the magnetic field generated by the ionic current makes the NWs to act as nano-stirrers, improving the local flow of material towards the active sites of the catalyst. During cyclic voltammetry experiments magnetic nanowires move back and forth in a given direction at the liquid/liquid interface according to the direction of polarization.Fil: Riva, Julieta Soledad. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Juárez, Andrea Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Yudi, Lidia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Magnetization mechanisms in ordered arrays of polycrystalline Fe100-xCox nanowires

Magnetization reversal processes and coercivity mechanisms in polycrystalline Fe100-xCox nanowire arrays, resulting from an AC electrodeposition process, are investigated. The array coercivity is described on the basis of polarization reversal mechanisms operating in individual wires, under the effect of inter-wire dipolar interactions described by a mean field approximation. For individual wires, a reversal mechanism involving the nucleation and further expansion of domain-wall like spin configuration is considered. The wires have a mean grain size larger than both the nanowire diameter and the exchange length, so localized and non-cooperative nucleation modes are considered. As the Co content increases, the alloy saturation polarization gradually decreases, but the coercive field and the relative remanence of the arrays increase, indicating that they are not controlled by the shape anisotropy in all the composition range. The coercive field dependence on the angle between the applied field and the wire long axis is not well described by reversal mechanisms involving nucleation and further displacement of neither vortex nor transverse ideal domain walls. On the contrary, the angular dependence of the coercive field observed at room temperature is well predicted by a model considering nucleation of inverse domains by localized curling, in regions smaller than the grain size, exhibiting quite small aspect ratios as compared to those of the entire nanowire. In arrays with higher Co contents, a transition from an initial (small angle) localized curling nucleation mechanism to another one, involving localized coherent rotation is observed at about π/4.Fil: Viqueira, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Bajales Luna, Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Bercoff, Paula Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

Co100-xFex magnetic thick films prepared by electrodeposition

Co-Fe films are grown onto plane pre-treated Cu foils; the effects of the alloy composition on the morphology and the crystal texture of the electrodeposited films and their anisotropic magnetic hysteresis properties are explored. Nucleation and crystallization mechanisms in these Co-rich layers are also investigated with pulse-reverse plating techniques, using the first cathodic pulse current-time transients. In the diffusion controlled regime the deposition mechanism is found to involve progressive nucleation with three-dimensional (3D) growth, except for the equiatomic Fe50Co50 solution where nucleation tends to become instantaneous. The different morphologies and size scales observed are described and correlated with coercivity. The films are electrodeposited onto electrochemically pre-treated Cu substrates from feeds of nominal Fe/Co mol ratios between 0/100 and 50/50. The composition of the deposited layers, as determined by energy dispersive X-ray spectroscopy, are quite close to the nominal values. Cyclic voltammetry determinations exhibit only a single reduction process on the cathode, indicating that a unique (Co100-xFex) phase grows. Depending on composition and on the substrate pre-treatment, these layers exhibit textures with features of different sizes. X ray diffraction patterns indicate that the nanostructures with Fe contents above 20 at.% crystallize in a body-centered cubic cell, while samples with Fe contents below this value are fcc. Regarding the effect of composition on the morphology, Co and Co-rich layers are compact, with large (100-300 nm) agglomerates of quite equiaxed, densely packed particles (average 50 nm); as the iron content increases above 15 at.%, faceted particles 100 nm in size are observed. All the electrodeposited layers are soft ferromagnetic at room temperature, with an in plane easy axis; coercive fields/forces between 10 mT and 71 mT are measured at 300 K.Fil: Aguirre, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Farias, Eliana Desiree. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Abraham, J.. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Urreta, Silvia Elena. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin