Identification of the consequences of Pb-O chemical bond modification, Pb lone pair and Pb volatilization on the intrinsic and extrinsic physical properties of Ba1-xPbxTiO3 (x ≤ 0–0.5)

Abstract

In classical ferroelectric BaTiO3, inclusion of Pb at A-site, forms a unique system in terms of improvement in the physical properties and for investigation of several interesting aspects associated with the physical chemistry and materials science. Manipulation of ferroelectric instability with high tetragonality arises due to Pb-O bond which exhibits strong covalent nature along with the presence of the stereochemically active lone pair of Pb (i.e. 6s2). In contrast, Ba-O chemical bond is ionic in nature. In the present work, Pb is progressively substituted with Ba, to observe the intrinsic effects on the physical properties such as tetragonality, phase transition temperature, vibrational modes, piezoelectric coefficient, ferroelectric domain configuration etc. Phase transition temperature significantly increases with substitution of Pb, which is a manifestation of the effect of chemical bond modification. Sintering temperature effects both intrinsic as well as extrinsic contributions to the physical properties of the system.