Anomalous Sintering Behavior of (Sr0.7La0.3)1-xTiO3+δ Perovskites (0 ≤ x ≤ 0.12)Synthesized by the Pechini Method

Abstract

The crystal structure, phase relationship and sintering characteristics of (Sr0.7La0.3)1-xTiO3 perovskites (0<x<0.12) have been studied using the Pechini method. From the results of high-temperature neutron diffraction analysis, it was clear that (Sr0.7La0.3)TiO3 showed an orthorhombic structure at room temperature and a cubic structure at 450 degree C. (Sr0.7La0.3)0.88TiO3 showed a single perovskite phase and other samples with an A-site deficiency of 0<x<0.08 included Ruddlesden-Popper phases as second phases. Sintering characteristics had a tendency to improve with increasing A-site deficiency. It was found that during sintering, (Sr0.7La0.3)0.88TiO3 expanded anomalously between 1400 degree C and 1500 degree C and for holding times between zero and 10 h at degree C and 1500 degree C. SEM observation of the samples showed that this expansion was caused by pore formation within the samples.