Dielectric responses and scaling behaviors in Aurivillius Bi ₆Ti ₃Fe ₂O ₁₈ multiferroic thin films

Dielectric responses and scaling behaviors of Aurivillius Bi ₆Ti ₃Fe ₂O ₁₈ (BTF2) multiferroic thin films were systemically detailed by the temperature-dependent dielectric/impedance spectroscopy. We clarified two dielectric relaxation processes presented in grain interior of the BTF2 films. One relaxation below ∼500 K was proposed to associate with the localized hopping process of carrier between Fe ³ and Fe ² inside the grains. Another one above ∼500 K arose from the long-range movement of oxygen vacancies. The scaling behaviors implied that the distribution of relaxation times for oxygen vacancies was temperature independent while the dynamical processes for the hopping carriers presumably depended on temperature.