No abstract

This study reports significant differences in the defect-mediated electrostrain in B-site trivalent ions (Fe3+ and Mn3+) doped Barium titanate based system. Electron Paramagnetic Resonance (EPR) Spectroscopy has been employed as a structural probe for understanding the symmetry of defects. Differences in the reorientation of the defect dipoles have been correlated with the electrostrain. Mechanism for the higher strain in Mn-doped system has also been explained.

In ferroelectric BaTiO3, we report the evolution of the Dielectric Relaxor and Ferroelectric Relaxor states as a function of B-site doped Al3+ concentration. The relaxor states occur after the paraelectric-ferroelectric phase transition upon cooling. Two different mechanisms are proposed; one based on migration of oxygen vacancies for symmetry-confirmation and the other based on disruption of long-range ferroelectric order by high concentrations of Al3+ ions at the B-site.