SrTiO3–SrZrO3 solid solution: Phase formation kinetics and mechanism through solid-oxide reaction

Abstract The perovskite solid solution composition Sr(Ti 0.5 Zr 0.5 )O 3 (STZ (ss)) has been synthesized from the mixture of SrCO 3 , TiO 2 and ZrO 2 powders through solid-state reaction. The phase formation mechanism and kinetics were investigated using TG/DSC, XRD. SrCO 3 in the precursor decomposes at relatively lower temperature than pure powder decomposition, due to the presence of acidic TiO 2 . Upon calcinations of the precursor SrTiO 3 (ST) and SrZrO 3 (SZ) were formed separately in the system. Then ST defuses in to SZ to form STZ (ss). ST formation started at lower temperature (800 °C) with lower activation energy (47.274 kcal/mol) than SZ. SZ formation started at 1000 °C with high activation energy (65.78 kcal/mol). STZ (ss) formation started from 1500 °C with very high activation energy (297.52 kcal/mol). It is concluded that solid solution formed coherently with SZ lattice by the diffusion of Ti in to the SZ.