Measurement of Dielectric Properties of Ultrafine BaTiO₃ Using an Organic–Inorganic Composite Method

Ultrafine BaTiO₃, unlike traditional ferroelectric materials, demonstrates some interesting dielectric properties, such as a gradual transition from paraelectric to ferroelectric phase, which is similar to dielectric relaxation ferroelectrics. Although several methods have been recently proposed to measure the dielectric properties of ultrafine BaTiO₃, the problem still remains unsolved. This paper proposes a new method to estimate the dielectric properties of ultrafine BaTiO₃ by measuring and analyzing the dielectric properties of BaTiO₃–epoxy composites. The Novocontrol dielectric measuring system was employed to measure the dielectric response of the composites. The dielectric behavior and relaxation characteristics of the BaTiO₃ filler were estimated by modeling and calculating the dielectric constant based on different mixture theories. Results reveal that the effect of surface states yields dielectric relaxation in ultrafine BaTiO₃.