Abstract
The effect of different regimes of combustion of glycine–nitrate precursors on the formation of perovskite phases (LaMnO3 and LaCrO3) without additional heat treatment was studied. The following three combustion regimes were compared: the traditional solution combustion synthesis (SCS), volume combustion synthesis (VCS) using a powdered precursor, and self-propagating high-temperature synthesis (SHS) using a precursor pellet. The products of combustion were studied using a series of physicochemical methods (attenuated total reflection infrared spectroscopy (ATR FTIR), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and thermal analysis). SHS was found to be the most productive regime for the formation of perovskite because of its ability to develop high temperatures in the reaction zone, which led to a reduced content of the thermally stable lanthanum carbonate impurities and to an increased yield and crystallite size of the perovskite phase. The reasons for the better crystallinity and purity of LaCrO3 as compared with LaMnO3 is also discussed, namely the low temperatures of the onset of the thermolysis, the fast rate of combustion, and the favorable thermodynamics for the achievement of high temperatures in the reaction zone.
Highlights
The utilization of the heat of chemical reactions in the synthesis of various inorganic compounds was first proposed by a group of Soviet scientists under the guidance of Academician A.G
The elemental stoichiometric coefficient (φ) of the precursor, its combustion conditions, and and additional calcination are the main factors determining the formation of the crystalline phase of additional calcination are the main factors determining the formation of the crystalline phase of perovskite
It is worth noting that these data (Table 3) are difficult to analyze since all the characteristics perovskite
Summary
The utilization of the heat of chemical reactions in the synthesis of various inorganic compounds was first proposed by a group of Soviet scientists under the guidance of Academician A.G. The first intensive studies in this area were performed for systems that burn without the evolution of gases, for example, in the synthesis of borides, carbides, and silicides of different metals. Later, these studies were extended to include the processes of combustion taking place with the evolution of gaseous products and the formation of a solid combustion product. These studies were extended to include the processes of combustion taking place with the evolution of gaseous products and the formation of a solid combustion product Such processes were called SHS [3,4,5,6,7,8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
