Fig shows the relative permittivity r

Generally, at a low frequency the relative permittivity of the ceramics decreased with increasing frequency. The relative permittivity of ceramics BVD 10 attributed to four types of polarizations: interfacial, dipolar, atomic and electronic. At low frequencies, where all four types of polarization are involved, the relative permittivity and the dielectric loss are very high. The relative permittivity and the dielectric loss gradually decrease due to the increase in the frequency, which is due to the presence of only small-object polarizations (atomic and electronic) and the disappearance of the other two types. The interfacial polarization occurs up to frequencies of around 3 MHz. That is somites why the losses did not decrease below the value of about 0.2 at 1 MHz for the as-sprayed sample. With further frequency increase the relative permittivity, as well as dielectric loss, would be saturated because the electronic exchange cannot follow the AC field beyond a certain critical frequency [26].