Nanocomposites of Iron−Cobalt Alloy and Magnetite: Controllable Solvothermal Synthesis and Their Magnetic Properties

Abstract

Nanocomposites of Fe-Co alloy and cobalt-substituted magnetite magnetic materials Fe x Co 1-x /Co y Re z Fe 3-y-z O 4 (Re ) none, La, Nd, and Gd) have been obtained successfully employing a surfactant-assisted solvothermal method. The nanocomposite features hard and soft magnetic phases juxtaposed within one discrete, anisotropic structure. Sodium oleate molecules were found effective in preventing the oxidation of the Fe-Co alloy and aggregation of the magnetic microspheres. X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy were used to characterize the structure and the morphology of the products. The result of magnetic characterization reveals that the magnetic microspheres exhibit a ferromagnetic behavior and possess high saturation magnetization and low coercivity. It is expected that these magnetic microspheres with uniform size would have potential applications such as magnetic carriers for drug targeting because of their excellent soft-magnetic properties.

Magnetically Separable Nanocatalysts: Bridges between Homogeneous and Heterogeneous Catalysis

“…(3) yields a mean particle size of 230-270 nm for the average size of the magnetite phases in Fe-Co/ magnetite nanocomposites. [107] Below a particle size of about 3 nm, other scattering techniques such as small-angle X-ray scattering (SAXS) or small-angle neutron scattering (SANS) can be used to obtain mean particle sizes as well as size distributions. [108] Small-angle scattering is scattering which occurs for small values of the scattering vectors s, the magnitude of which is defined by Equation (4).…”

Controllable synthesis and magnetic property of Fe/Fe3O4 polyhedron synthesized by solvothermal method

“…on B-sites of magnetite; and the other is the percentage of Fe in the composite. It should be apparent from the mechanism of the composite formation that the system is consisted of ferromagnetic (Fe) and ferromagnetic (Fe 3 O 4 ) [10]. This means that there would be exchange coupling between the Fe and Fe 3 O 4 .…”

“…Much of the existing research has paid more attention to the synthesis and morphological organization of phase-pure magnetic materials [6][7][8][9][10]. Among magnetic materials, Fe/Fe 3 O 4 composite system has attracted much attention due to its favorable magnetoelectric and transport properties [11][12][13][14][15].…”

Magnetisch abtrennbare Nanokatalysatoren: Brücken zwischen homogener und heterogener Katalyse

“…Bei der Bestimmung des mittleren Durchmessers der Magnetitphasen in Fe‐Co‐Magnetitnanokompositen ergab die Linienbreitenanalyse des (311)‐Peaks entsprechend Gleichung (3) mittlere Teilchendurchmesser von 230–270 nm 107. Unterhalb einer Partikelgröße von ca.…”