Confined growth of highly uniform and single bcc-phased FeCo/graphitic-shell nanocrystals in SBA-15

Carbon-coated FeCo nanoparticles as sensitive magnetic-particle-imaging tracers with photothermal and magnetothermal properties

“…Future research in the FeCo nanoparticle synthesis may further improve their magnetic properties and thereby MPI signals, for example, varying particle size (from 10 to 50 nm), tuning crystalline structure and reaction conditions. 50 This work demonstrates the feasibility of designing MPI tracers beyond iron oxides. Other types of magnetic particles, such as AuFe 3 , FePt, Nd 2 Fe 14 B, Fe, Fe 5 C 2 , and FeS nanoparticles, may also be explored in search for more sensitive MPI tracers.…”

Transforming a Diamagnetic Ordered Mesoporous Silica Monolith into a Room Temperature Permanent Magnet through Multiscale Control of the Magnetic Properties

“…Spherical nanoparticles embedded in discontinuous Co 0.8 Fe 0.2 /Al 2 O 3 multilayers have been extensively studied showing various magnetic behaviors ranging from superspin glass to superferromagnetism depending on the Nps’ density ,. Mesoporous silica were used to grow magnetic nanoparticles with controlled particle size, but mainly the magnetic properties of the 5–6 nm nanocrystals after silica dissolution were reported . Functionalized mesoporous silica nanospheres (65 to 270 nm) containing 4.6 nm FeCo/graphitic carbon shell nanocrystals (magnetic metal content of 8.35 wt%) and prepared by impregnation with a mixture of nitrate salts, designed for wastewater treatment, were shown to be magnetically recyclable .…”

“…Some works report on the magnetic properties of assemblies of superparamagnetic Nps embedded in a solid matrix : Fe Nps embedded in alumina films, maghemite Nps in polymer particles, NiFe alloy Nps in alumina film, magnetite Nps in calcium silicate monoliths, CoFe alloy Nps in amorphous alumina films, FeCo alloy Nps in mesoporous silica SBA‐15 particles, CoFe 2 O 4 Nps in silica, Co x Fe 1‐x and Fe 2 O 3 as well as Pd and PdO Nps in mesoporous silica MCM41 particles, Pt and Fe 2 O 3 Nps in mesoporous silica nanofibers with coaxial helical/columnar mesostructures, Prussian blue analog (PBA) nanoparticles embedded in ordered mesoporous silica… All these examples show the great opportunities and the flexibility offered by such nanocomposites to design magnetic materials with unexpected properties, but they also show that the properties of the different samples are not directly comparable and strongly depend on the preparation method. Indeed, many factors influence the properties of the final materials: chemical composition, structure, shape, and orientation of the nanoparticles within the matrix, their aggregation state as well as their interactions with the matrix and their spatial organization.…”

Impregnation of High-Magnetization FeCo Nanoparticles in Mesoporous Silicon: An Experimental Approach

“…More specifically, employment of nanosized magnetic materials show an improved reactive surface area and their insertion in a porous medium is one of the solutions to prevent their mutual aggregation and sintering during reaction (Lu et al, 2004; Bomati-Miguel et al, 2005). Porous substrates made of different materials such as PEGDA (polyethylene glycol diacrylate; Allia et al, 2011), silicon (Anglin et al, 2008; Granitzer et al, 2010; Harraz, 2013) or silica (Lu et al, 2004; Nakamura et al, 2006; Kockrick et al, 2007; Zhu et al, 2009; Liu et al, 2011; Kim et al, 2013) can be used as supports. In particular, porous silicon (PS) is one of the most interesting media because it is a versatile material with tunable surface chemistry, pore size or surface area (Loni et al, 2015) and shows interesting behavior concerning biodegradability issues (Xia et al, 2017).…”