Composition and shape control of single-crystalline Ba1-xSrxTiO3 (x=0-1) nanocrystals via a solvothermal route

Single-crystalline and well-dispersed barium strontium titanate (Ba1-xSrxTiO3, x = 0-1, BST) nanocrystals have been successfully synthesized in a shape- and composition-controlled manner using a facile solvothermal route. The microstructure and composition of the as-synthesized samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and energy-dispersive X-ray spectroscopy (EDX). All the samples were identified as cubic perkovsite phase by XRD. The average particle sizes, morphologies and compositions of all the as-synthesized samples significantly depend on the Ba/Sr molar ratio in the initial reactants. The particle size gradually increases and the morphology ranges from irregular sphere to cube as the strontium proportion increases in the BST. It has also been found that, in all cases, strontium is more readily incorporated into the BST nanocrystals compared with barium. Further experiments display that highly dispersed BaTiO3 and SrTiO3 nanocrystals could also be obtained with an acceptable crystallinity at room temperature by this solvothermal method. (C) 2008 Elsevier B.V. All rights reserved.