Influence of Li2Co3 and V2O5 combined additions on the sintering and dielectric properties of Ca0.5Sr0.5TiO3 ceramics prepared from powders synthesized by sol-gel method

Abstract

In this work, we have studied the influence of lithium carbonate (Li2CO3) associated with the vanadium oxide (V2O5) on sintering and dielectrics properties of Ca0.5Sr0.5TiO3 ceramic materials obtained from nanopowder synthesized by sol-gel method. The nanopowder was obtained by controlled mixing of titanium butoxide dissolved in butanol-2 and acetic acid with a saturated aqueous solution of calcium acetate and strontium carbonate and subsequent drying of the formed gel at 80 ?C and calcination at 1100?C. The synthesized nanopowder was mixed with different amount of additives, and then uniaxally pressed and sintered in air atmosphere at temperature determined by dilatomertic measurements. The pure Ca0.5Sr0.5TiO3 sample obtained by this process required a sintering temperature around 1500?C. The addition of Li2CO3 combined with V2O5 improved sinterability and caused a shift of dilatimeric shrinkage curve to much lower temperatures. Thus, dense ceramics (98% of theoretical density) were obtained at sintering temperature ? 1300?C. The effect of adding Li2CO3-V2O5 on the structure of ceramics and the dielectric properties is discussed and show that type I dielectric properties (linear variation of the permittivity) are conserved, but with an increase of dielectric loss.