Structural Behaviour of Solid Solutions in the NdAlO3-SrTiO3 System.

Single-phase mixed aluminates-titanates Nd Sr Al Ti O (x = 0.3 ÷ 0.9) were prepared from stoichiometric amounts of constituent oxides NdO, AlO, TiO and strontium carbonate SrCO by solid-state reaction technique in air at 1773 K. Crystal structure parameters of Nd Sr Al Ti O were refined by full-profile Rietveld refinement in space groups R [Formula: see text] c (x = 0.3, 0.5, 0.7 and 0.8) and Pm [Formula: see text] m (x = 0.9). Comparison of the obtained structural parameters with the literature data for the end members of the system NdAlO and SrTiO revealed formation of two kinds of solid solutions NdSrAlTiO with the cubic and rhombohedral perovskite structure. Morphotropic rhombohedral-to-cubic phase transition in NdSrAlTiO series occurs at x = 0.84. Based on the results obtained as well as the literature data for the parent compounds, the tentative phase diagram of the NdAlO-SrTiO pseudo-binary system have been constructed.