Dielectric and electrical conductivity studies of bulk lead (II) oxide (PbO)

The dielectric properties, the impedance spectroscopy and AC conductivity of bulk PbO have been investigated as a function of frequency and temperature. The measurements were carried out in the frequency range from 40 to 5 x 10(6) Hz and in temperature range from 313 to 523 K. The frequency response of dielectric constant, epsilon(1), and dielectric loss index, epsilon(2), as a function of temperature were studied. The values of epsilon(1) and epsilon(2) were found to decrease with the increase in frequency. However, they increase with the increase in temperature. The presence of a single arc in the complex modulus spectrum at different temperatures confirms the single-phase character of the PbO. The AC conductivity exhibited a universal dynamic response: sigma(AC) = A omega(5). The AC conductivity was also found to increase with increasing temperature and frequency. The correlation barrier hopping (CBH) model was found to apply to the AC conductivity data. The calculated values of s were decreased with temperature. This behavior reveals that the conduction mechanism for PbO samples is CBH. The activation energy for AC conductivity decreases with increasing frequency. This confirms that the hopping conduction to the dominant mechanism for PbO samples. (C) 2013 Elsevier B.V. All rights reserved.