We described the methodology and results of measuring the relative dielectric permittivity εr of nickel-zinc ferrite M200VNP and M1000NN in the frequency range of 1–100 kHz. At frequencies below 50 kHz the investigated types of ferrites exhibit interfacial polarization, leading to abnormally high values of ε. At higher frequencies ε decreases to a constant value of approximately 12.
Patrakov et al. (Wed,) studied this question.