Structural Behaviour of Solid Solutions in the NdAlO3-SrTiO3 System

Single-phase mixed aluminates-titanates Nd(1-x)Sr(x)Al(1-x)Ti(x)O(3) (x = 0.3 ÷ 0.9) were prepared from stoichiometric amounts of constituent oxides Nd(2)O(3), Al(2)O(3), TiO(2) and strontium carbonate SrCO(3) by solid-state reaction technique in air at 1773 K. Crystal structure parameters of Nd(1-x)Sr(x)Al(1-x)Ti(x)O(3) 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(3) and SrTiO(3) revealed formation of two kinds of solid solutions Nd(1-x)Sr(x)Al(1-x)Ti(x)O(3) with the cubic and rhombohedral perovskite structure. Morphotropic rhombohedral-to-cubic phase transition in Nd(1-x)Sr(x)Al(1-x)Ti(x)O(3) 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(3)–SrTiO(3) pseudo-binary system have been constructed.