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Influence of the borohydride concentration on the composition of the amorphous ...

A systematic study of the effect of the NaBH4 concentration upon the composites produced by chemical reduction of nano-sized goethite (_-FeOOH) particles suspended in water is presented. Amorphous Fe–B alloys with boron contents between 2 and 8 at.% have been produced. The obtained samples were characterized by X-ray diffraction, wet chemical analyses, thermal analyses, scanning electron microscopy, transmissio...

Synthesis and characterisation of some iron oxides by Sol-gel method.

Low-temperature Mossbauer study of heterosite, (Fe, Mn)PO4.

The heterosite phase occurring in a pegmatitic rock sample was characterized by X-ray diffraction, by energy-dispersive X-ray spectroscopy and by Mossbauer spectroscopy. The orthorhombic unit-cell parameters, expressed in A˚ , were found as a = 9.733 (1), b = 5.837 (1) and c = 4.776 (1). The composition was determined to be (Fe0.54Mn0.43Mg0.04)PO4. Mossbauer spectra recorded at temperatures T of 65K and higher ...

Characterization of soil-oxide analogues by applied-field Mossbauer spectroscopy.

In this contribution, the effect of high external magnetic fields upon the Mössbauer spectra of aluminous _- and -Fe2O3, of aluminous _- and -FeOOH and of aluminous Fe3O4 is reviewed. It is shown that the shapes of these spectra are characteristic of these materials and also to some extent of their crystallinities and Al-for-Fe substitutions. Based upon this evaluation, the potential for application of external...

Study of loss-on-ignition anomalies found in ashes from combustion of iron-rich...

Samples of a fly and a bottom ash, each before and after ignition at 960 _C, have been studied by X-ray diffraction, Mössbauer spectroscopy, carbon analysis, and thermogravimetric analysis with the aim to explain an observed negative loss on ignition. Ashes after ignition contain more maghemite resulting from oxidation of newly formed magnetite. Moreover, the fly ash that already contained magnetite exhibited a...