Reactive sintering of phosphorous coated BaTiO3

Abstract Doping BaTiO 3 with P 5+ has been reported to decrease the sintering temperature of the ceramic, allowing homogeneous fine grained microstructures to be obtained. According to the present paper, the formation of a phosphorous-BaO rich phase covering the BaTiO 3 particles seems to be the origin of the improved porosity coalescence and removal observed at the earlier sintering stage of these materials. The formation and development of phosphorous-barium rich phases have been followed by means of DRX, and high temperature NMR. Phosphorous cations incorporated from phosphate ester form a surface layer covering the BaTiO 3 particles which reacts during heating to form Ba 2 TiP 2 O 9 and/or Ba 3 (PO 4 ) 2 . Formation of these phases seem to occur by solid-solid reaction involving phosphorous diffusion through the BaTiO 3 particles.