Mechanical stimulation of gasless reaction in inorganic systems: A mini review
Not provided.
Energy & Fuels↗
Engineering topics
Mukasyan, Alexander S.
Publications and source records attributed to Mukasyan, Alexander S..
Shock-induced reactions in metal nitride – Boron nanostructured composites
Not Available
Chapman, Wesley W.↗
Mechanisms of mechanochemical synthesis of cesium lead halides: pathways toward stabilization of α-CsPbI 3
Cesium lead iodide with cubic perovskite structure (α-CsPbI 3 ) is gaining significant interest in photovoltaic applications due to its excellent absorbance of the visible solar light and other attractive optoelectronic properties. However, the synthesis of stable α-CsPbI 3 poses a significant challenge. Mechanochemical synthesis is emerging as a suitable method for the preparation of cesium lead halides. This work investigates the ball milling-induced synthesis of cesium lead halides perovskite phase using halide mixing or doping approaches. The synthesis in the CsI + PbI 2 , CsBr + PbBr 2 , CsBr + PbI 2 , and CsI + PbI 2 + NdI 3 mixtures and halide exchange reactions in the CsPbBr 3 + 3KI and CsBr + PbBr 2 + 3KI systems are investigated to elucidate the mechanism of this process. Then, CsPb(I 1–x Br x ) 3 and CsPb( 1–y )Nd y I 3 materials with different x and y ratios are prepared, and their stability is probed in the air using light absorption spectroscopy. These results suggest that Nd doping is more efficient in the stabilization of the perovskite structure than partial replacement of iodine with bromine. Microstructure observations reveal the existence of two different product formation mechanisms depending on the mechanical properties of reactants. The results reveal that the milling temperature has a significant impact on the reaction kinetics. Here, the produced particles nucleate and grow at the reactant interface and retard the synthesis reaction by creating a diffusion barrier. Extended milling reduces the product particle size and creates fresh contact between reactants, thus facilitating reaction completion.
36 MATERIALS SCIENCE↗
SHS Ceramics: History and Recent Advances
In this paper, we focus on some historical aspects, as well as on recent achievements in the field of self-propagating high-temperature synthesis (SHS) of ceramics. While giving the tributes to the pioneers of the SHS, we overview the wide variety of recently established SHS-based routes for fabrication of advanced ceramics, including nanopowders and nanostructured bulk materials. Both, the conventional heterogeneous SHS and solution combustion synthesis (SCS) approaches are considered. Advantages and challenges for using of the self-sustained reactions for fabrication of ceramics are also discussed.
36 MATERIALS SCIENCE↗
Nanoscale Metastable ε-Fe 3 N Ferromagnetic Materials by Self-Sustained Reactions
A single-step method for the preparation of metastable ε-Fe 3 N nanoparticles by combustion of reactive gels containing iron nitrate (Fe(NO 3 ) 3 ) and hexamethylenetetramine (C 6 H 12 N 4 ) in an inert atmosphere is reported. The results of Fourier transform infrared spectroscopy (FTIR) and thermal analysis coupled with dynamic mass spectrometry revealed that the exothermic decomposition of a coordination complex formed between Fe(NO 3 ) 3 and HMTA is responsible for the formation of ε-Fe 3 N nanoscale particles with sizes of 5-15 nm. The magnetic properties between 5 and 350 K are characterized using a superconducting quantum interference device (SQUID) magnetometer, revealing a ferromagnetic behavior with a low-temperature magnetic moment of 1.09 μB/Fe, high room temperature saturation magnetization (~80 emu/g), and low remanent magnetization (~15 emu/g). The obtained value for the Curie temperature of ~522 K is close to that (~575 K) for bulk ε-Fe 3 N reported in the literature.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗