Fabrication and characteristics of strontium barium niobate/barium strontium titanate ceramics by powder-sol method

Barium strontium titanate (Ba1-xSrxTiO3, BST) and strontium barium niobate (SrxBa1-xNb2O6, SBN) are important ferroelectric materials with excellent pyroelectric, dielectric properties and faster response time of infrared radiation. SBN/BST composite ceramics with different mole ratios of Nb and Ti were fabricated using a powder-sol (P-S) method with Nb2O5 fine powders suspended in the barium strontium titanate (BST in short) sol solution. The X-ray diffraction results indicate that three intermediate phases, i.e. TiO2, BaNb2O6 and SrNb2O6, are developed during the formation of SBN-BST. Powders obtained from dried gels are calcined at 800 degrees C for 3 h. The Ti-2p spectra of only one spin-orbit doublet are observed, which indicates one 4+ chemical state in the composite ceramics. The binding energies of Nb element depend strongly on composition.