Abstract
The effect of Tb3+ substitution at B site of nanoparticulateBiFeO(3)on various dielectric parameters was evaluated at room temperature in the frequency range of 1 MHz to 3 GHz. The value of x (i.e. Tb contents) was in the range of 0.00 to 0.02. Materials that have high dielectric constant cause resist the penetration of electromagnetic waves; therefore for devices working at high frequencies the low dielectric constant materials are preferred. The minimum dielectric constant (27.65) was observed at 3 GHz for Tb0.008Bi0.992FeO3, however the maximum dielectric constant (87.56) was observed for Tb0.012Bi0.88FeO3 at similar to 1.00 MHz. Similar trends were observed for dielectric loss and tand values. In general for all compositions usually low dielectric constant, dielectric loss and tand were observed that suggest the applications of these materials for fabrications of devices that are required to operate at higher (GHz) frequencies range. Besides main types of dielectric parameters, the other parameters related to dielectric behavior such as ac-conductivity (sigma(ac)), the electrical modulus (M) etc were also evaluated. The ac-conductivity was found to increase with increased frequency and the maximum ac-conductivity was observed for Tb0.012Bi0.88FeO3 nanoparticles. The mechanism of charge transport processes by electrical transport; ion dynamics and conductivity relaxation have also been explained in detail.