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A. Gheisi, M. Niedermaier, G. Tippelt, W. Lottermoser, J. Bernardi, O. Diwald:
"Iron Precursor Decomposition in the Magnesium Combustion Flame: A New Approach for the Synthesis of Particulate Metal Oxide Nanocomposites";
Particle & Particle Systems Characterization, 1700109 (2017).

Powders of Fe-Mg-O nanocomposite particles have been grown using a
novel chemical vapor synthesis approach that employs the decomposition
of a metalorganic precursor inside the metal combustion flame. After
annealing in controlled gas atmospheres composition distribution functions,
structure and phase stability of the obtained magnesiowüstite nanoparticles
are measured with a combination of techniques such as inductively coupled
plasma-optical emission spectroscopy, energy dispersive X-ray spectroscopy,
X-ray diffraction, and scanning and transmission electron microscopy. Complementary
Mössbauer spectroscopy measurements reveal that depending
on Fe loading and temperature of annealing either metastable and superparamagnetic
solid solutions of Fe3+ ions in periclase (MgO) or phase separated
mixtures of MgO and ferrimagnetic magnesioferrite (MgFe2O4) nanoparticles
can be obtained. The described combustion technique represents a novel
concept for the production of mixed metal oxide nanoparticles. Adressing the
impact of selected annealing protocols, this study underlines the great potential
of vapor phase grown non-equilibrium solids, where thermal processing
provides means to trigger phase separation and, concomitantly, the emergence
of new magnetic properties.

http://dx.doi.org/10.1002/ppsc.201700109