Dielectric studies in a layered Ba based Bi-2222 cuprate Bi2Ba2Nd1.6Ce0.4Cu2O10+δ

The ceramic sample of a layered cuprate Bi2Ba2Nd1.6Ce0.4Cu2O10+δ, so-called Ba-based Bi-2222 compound was investigated by the measurement of the dielectric permittivity and the dissipation factor as a function of temperature (80-300 K) and frequency (20-106 Hz). The dielectric constant was measured as high as ∼1000 at 1 kHz and 300 K with relatively low dissipation factor. However, it decreases systematically with decreasing temperature or with increasing frequency due to the dipolar relaxation process. This thermally activated relaxation process plays a dominant role for the low frequency dielectric response. The associated relaxation time obeys Arrhenius' relation with the activation energy of 0.60 eV. And we propose that this dipolar polarization may mainly originate from the hopping of charge carriers between localized sites over the potential barriers.