Figure 3(a) shows the temperature d

Figure 3(a) shows the temperature dependence of dielectric properties. The room temperature permittivity is 1830 and 690 for BT-150nm and BT-75nm, respectively. The high permittivities and distinct Ferroelectric-Paraelectric phase transition indicate the dielectric properties are comparable to those sintered at high temperature. As Figure 3(a) shows, smaller grain size (BT 75nm) shows a lower dielectric permittivity at measured temperature range. The difference in the dielectric permittivity is explained in terms of the intrinsic size effect below 100 nm. Arlt et al and others explained that the maximum of the permittivity appears around grain sizes of 0.8-1 µm due to the 90º domain extrinsic contribution. Below this size, the permittivity constantly decreases due to the decrease of the tetragonality[33,35].