Electrical and X-ray Photoelectron Spectroscopy Study on (Na0.5-xKxBi0.5-xNdx)TiO3 Ceramics

Abstract

The (Na0.5-xKxBi0.5-xNdx)TiO3 ferroelectric ceramics with x = 0.0125, 0.025 and 0.05 were prepared by solid state reaction route. The dielectric, ferroelectric property and X-ray photoelectron spectroscopy (XPS) studies were investigated on the prepared samples. X-ray studies indicate the formation of single phase perovskite structure with rhombohedral symmetry. Ceramic composition with x = 0.025 exhibit high ferroelectric property with remanent polarization (Pr) around 13.89 μC/cm2 at coercive filed (Ec) ∼ 46.05 kV/cm when compared to other compositions. Lower value of remanent polarization for present ceramic materials when compared to pure sodium bismuth titanate is attributed to domain wall clamping which restrains the macro-micro domain switching. XPS studies indicates that binding energy of Ti 2p and Bi 4f lines are consistent with only one chemical state, Ti+4 and Bi+3. On the other hand, in the case of O 1s XPS spectrum, apart from the main peaks attributed to the lattice ions in the perovskite material, extra peaks related to the adsorbed oxygen and oxygen vacancy were also observed.