Search results for "MANGANESE"

Synthesis and characterization of mesoporous Mn-MCM-41 materials

2011

Si { 1 H} CP-MAS NMR X-ray photo-emission spectroscopy a b s t r a c t MCM-41 has been synthesized at two different pH using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 ◦ C for 4 h. Mn-MCM-41 powders with different Mn/Si molar ratios were prepared using the incipient wetness method, followed by calcination at 550 ◦C for 5 h. At the end of the impregnation process the powders colour changed from white to brown whose intensity depends on manganese quantity. The materials characterization was performed by X-ray diffraction, N2 adsorption, 29 Si Cross Polarization–Mag…

Effect of surface microcracks on pitting susceptibility of manganese sulfide containing stainless steels

2007

A Metallacryptand-Based Manganese(II)–Cobalt(II) Ferrimagnet with a Three-Dimensional Honeycomb Open-Framework Architecture

2008

Structure and properties of CoMnSb in the context of half-metallic ferromagnetism

2006

Although its X-ray powder diffraction patterns show a superstructure, the compound CoMnSb, like the well-known half-Heusler alloy NiMnSb, is often referred to the category of half-metallic ferromagnets with $C{1}_{b}$ structure. Our study assigns CoMnSb to space group $Fm\overline{3}m$. The crystal structure of CoMnSb can be represented as an alternation of ${\mathrm{Co}}_{2}\mathrm{Mn}\mathrm{Sb}$ and MnSb structural units, and, in contrast to NiMnSb, displays three Mn and two Sb positions in the elementary cell. The presence of nonequivalent antimony and manganese positions was verified using NMR and M\"ossbauer spectroscopic measurements. Band-structure calculations based on a proposed s…

Au@MnO nanoflowers: hybrid nanocomposites for selective dual functionalization and imaging.

2010

Recently, the development of hybrid nanostructures consisting of various materials has attracted considerable interest. The assembly of different nanomaterials with specific optical, magnetic, or electronic properties to multicomponent composites can change and even enhance the properties of the individual constituents. Specifically tuning the structure and interface interactions within the nanocomposites has resulted in novel platforms of materials that may lead the way to various future technologies, such as synchronous biolabeling, protein separation and detection, heterogeneous catalysis, and multimodal imaging in biomedicine. Of the various kinds of nanomaterials, gold nanorods show an…

Manganese iron oxide superparamagnetic powder by mechanochemical processing. Nanoparticles functionalization and dispersion in a nanofluid

2012

Manganese ferrite nanoparticles were synthesized using a High-Energy Ball-Milling mechanochemical method. After 1 h of milling, the process produces a material consisting of single crystalline domain nanoparticles having a diameter of about 8 nm. Chemical properties of the synthesized powders allow an easy functionalization with citric acid. Both as-obtained and functionalized samples show superparamagnetic behaviour at room temperature, and the functionalized powder is stably dispersible in aqueous media at physiological pH. The average hydrodynamic diameter is equal to similar to 60 nm. Nanoparticles obtained by the reported High-Energy Ball-Milling method can be synthesized with high yie…

Domain wall transformations and hopping in La0.7Sr0.3MnO3nanostructures imaged with high resolution x-ray magnetic microscopy

2014

We investigate the effect of electric current pulse injection on domain walls in La(0.7)Sr(0.3)MnO(3) (LSMO) half-ring nanostructures by high resolution x-ray magnetic microscopy at room temperature. Due to the easily accessible Curie temperature of LSMO, we can employ reasonable current densities to induce the Joule heating necessary to observe effects such as hopping of the domain walls between different pinning sites and nucleation/annihilation events. Such effects are the dominant features close to the Curie temperature, while spin torque is found to play a small role close to room temperature. We are also able to observe thermally activated domain wall transformations and we find that,…

Mesoporous Silica-Confined Manganese Oxide Nanoparticles as Highly Efficient Catalysts for the Low-Temperature Elimination of Formaldehyde

2013

Inside Back Cover: Mesoporous Silica-Confined Manganese Oxide Nanoparticles as Highly Efficient Catalysts for the Low-Temperature Elimination of Form…

2014

Effects of electrolyte doping on electrodeposited nanostructured manganese oxide and chromium oxide

2020

Abstract Electrolyte additions are used to control the functionality of a nanostructured oxide. Dopant ions affect the size and shape of deposit crystallites and modify the host structure. Such ions can be incorporated into the deposit or form a separate oxide phase. The manganese dioxide family of polymorphs with ion-molecular sieve properties represents the additional possibilities of “template” effects of dopant ions on the phase composition, heterovalent substitution in the cationic sublattice, changes in morphology and alteration of nanocrystallite size during electrocrystallisation. The effects of electrolyte doping in electrodeposited, non-stoichiometric manganese dioxide (NH4+, Li+ …