THE EFFECT OF CALCINATION TEMPERATURE ON THE MICRO-STRUCTURE OF Sr5Nb4TiO17

The properties of dielectric materials are directly related to the microstructure, grain size and density. In the present study stoichiometric quantities of AR-grade raw powders of SrCO3, Nb2O5, TiO2 (Anatase) were used to synthesize Sr5Nb4TiO17 by solid-state sintering route. The reaction mixture was characterized by TGA/DTA to locate the formation temperature of Sr5Nb4TiO17 and to determine the phase transitions. The milled mixture was calcined at two different temperatures i.e. 990°C and 1350°C. Pellets of the calcined powders were made and sintered at 1500°C in air. The X-ray diffraction was used to identify the phase or phases present in the calcined powder as well as in the sintered samples. Micro-structural study of calcined powders as well as sintered samples, through SEM revealed Variation in the size and shape of the grains. The material sintered at 1500°C with calcination temperature of 990°C is more compact as compared to the sintered material with calcinations temperature of 1350°C.