Solid-state synthesis of SrY2O4 and SrSm2O4

Abstract

The course of solid-state synthesis of SrY2O4 and SrSm2O4 is described in this work. The processes during the thermal treatment, the mechanism and kinetics, the reactivity with water and the thermal stability of products were investigated by thermal analysis, isothermal calorimetry, infrared spectroscopy and scanning electron microscopy. Since solid-state synthesis does not show any significant effect on DTA, the course of synthesis was observed by the expansion of specimen. The kinetics of formation of SrY2O4 and SrSm2O4 is driven by the rate of reaction of 2nd order (g(α) = (1 − α)−1 − 1) and requires the Ea of 450 and 918 kJ mol−1, respectively. The heat released by the reaction of SrSm2O4 with water is significantly higher than that of SrY2O4. The introduction of Al2O3 to SrY2O4 led to the formation of monoclinic phase of Sr6Y2Al4O15. The hydraulic activity of these phases can be applied for the preparation of special inorganic cements.