A Cr3+ and F- composite-doped LiNi0.5Mn1.5O4 cathode material was synthesized by the solid-state method, and the influence of the doping amount on the material's physical and electrochemical properties was investigated. The structure and morphology of the cathode material were characterized by XRD, SEM, TEM, and HRTEM, and the results revealed that the sample exhibited clear spinel features. No...

Our study focuses on the structural evolution of MCM-41-supported iron oxide under the reducing environment of catalyst pretreatment and ethylbenzene dehydrogenation reaction. Powder X-ray diffraction (XRD) analysis showed that the iron oxide is well-dispersed on the surface of the support with no detectable diffraction peaks from iron oxide. X-ray absorption near edge structure (XANES) study i...

Introduction: Wark-Lovering (WL) rims [1] surrounding many refractory inclusions represent marker events in the early evolution of the Solar System in which many inclusions were exposed to changes in pressure [2], temperature [3], and isotopic reservoirs [4-7]. The effects of these events can be complex, not only producing mineralogical variability of WL rims [2], but also leading to mineralogi...

When highly divided spinel fenites become reactive enough with oxygen, to allow the oxidation of the Fe ions at low temperature and of substitute cations too, when these cations are capable of different valence states. We prepared fine particles of spinel ferrites substituted by Mn, Mo, Cu, by "chimie douce", especially from oxalate precursors and used them to reveal and to study the oxido-redu...

Silicon micromachined calorimeters ("calorimeter on a chip") are used to measure heat capacities and phase transition enthalpies for thin film, single crystal, and powder samples (5-500 mug). The technology is thus compatible with the small samples produced in multianvil and large diamond anvil cells. Techniques for handling small samples and attaching them to the calorimetric devices have been...

increasing demands for cement, iron and steel industries for refractories with suitable workability in severeconditions (without any environmental risks), make the refractories’ researches to be an active area. refractories containing spinel has been developed with addition of chromia as a substitute in refractories using magnesite - chromite. in this research, different amounts of cr2o3 were a...

The surface of non-stoichiometric nickel and nickel–copper spinel manganites has been investigated by X-ray Photoelectron Spectroscopy (XPS). The oxidation states of the nickel, copper and manganese cations present on the surface of the samples were 21 1 determined from the analysis of the M 2p core levels (M5Ni, Cu, Mn). In particular, both Cu and Cu were evidenced in the 3 / 2 structure where...

ncorporating Ni-laden waste sludge into kaolinite-based construction ceramic materials appears promising based on the identified nickel bearing hases, evaluated incorporation efficiency and nickel leachability of the products. Nickel aluminate spinel (NiAl2O4) results from sintering kaolinite nd nickel oxide between 990 and 1480 ◦C, with more than 90% incorporation efficiency achieved at 1250 ◦...

Iron cobaltite powders CoxFe3ÿxO4 (1rxr2.46) were synthesized with compositions in between the cobalt ferrite CoFe2O4 and Co2.46Fe0.54O4. The cationic distribution of pure spinel phases was determined by Mössbauer spectroscopy: as Co content increases in the spinel oxide, Co cations replace Fe cations in the octahedral sites and Co cations migrate from octahedral to tetrahedral sites. Saturatio...

Spinel-type ZnMn₂O₄ nanoparticles were synthesized via a simple and inexpensive microwave-assisted colloidal route. Structural studies by X-ray diffraction showed that a spinel crystal phase of ZnMn₂O₄ was obtained at a calcination temperature of 500 °C, which was confirmed by Raman and UV-vis characterizations. Spinel-type ZnMn₂O₄ nanoparticles with a size of 41 nm were identified by transmiss...