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In this study, a single-step combustion process for the synthesis 1-D, 2-D, and 3-D micro and nanostructures of AlN was developed. The structures were grown by combustion of Al+ k AlF 3 (or ZnF 2 )+ m NH 4 Cl reaction mixture under 4.0 MPa nitrogen atmosphere. Based on experimental data, the growth conditions, morphology, and composition, optical, and thermal properties of AlN micro and nanostructures were determined. The formation of structures was associated with the combustion temperature, liquid and gas-phase reactions, and the type of additives used in the experiments. The new insight, we gleaned from this study may help in the selective growth of AlN micro and nanostructures of different morphology, enhancing their functionality. [ABSTRACT FROM AUTHOR]

Abstract: An experimental study on the preparation of zirconium silicides was conducted using ZrSiO4–Mg, ZrSiO4–SiO2–Mg and ZrSiO4–ZrO2–Mg powder mixtures by the combustion synthesis (CS) technique. Test specimens having different composition ratios including Zr:Si=1:2, 1:1, 5:4, 5:3, 2:1, and 3:1 were employed in this study. Temperature profiles relative to all the starting compositions were measured using thermocouples, and the values of the combustion parameters (combustion temperature and wave velocity) were estimated using the same. The formation of ZrSi, ZrSi2, Zr5Si3, and Zr3Si2 phases was confirmed by X-ray analysis; however, only ZrSi was produced as a single-phase product. The proposed method was also extended to synthesize spherical ZrSi particles having mean diameters of 0.2–3.0μm. A comprehensive chemical pathway to describe the sequence of chemical reactions in the combustion wave was also proposed. [ABSTRACT FROM AUTHOR]