Synthesis and Characterization of BaTiO3-Based Ceramics Doped 81in B Site by BaTi1-xNbxO3

This chapter examines the effect of the addition of Nb5+ on the structure and electrical properties of barium titanate. The phases formed, the crystal structure and the microstructure of the samples were characterized using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The ceramic powders were dried in a type muffle oven for 24 hours. The sintered powders obtained for each composition were then mixed using an organic binder and pressed into green cylindrical disks of 10 mm diameter and about 5 mm height, at a pressure of about 200 MPa for 2 min in a stainless steel cylindrical die. When BaTiO3 passes through the tetragonal-cubic phase transition point, all the active Raman modes, in the tetragonal phase (P4mm), will be inactive in the perfect cubic phase (Pm3m), owing to forbidding of Raman selection rule. The less saturated hysteresis loops and the weaker ferroelectricity may be attributed to the formation of non-polar regions induced by the substitution of Nb5+ for B sites in BaTiO3 ceramics.