Electrical transport in Pb[(Ni1/3Sb2/3)xTiyZrz]O3 + 0.3% MnO

Results of studies on electrical transport in the polycrystalline ferroelectric Pb[(Ni1/3Sb2/3)xTiyZrz] O3 + 0.3% MnO, x = 0.08, y = 0.43–0.50 and x + y + z= 1, are reported and discussed in light of the theory of disordered solids. A.c. and d.c. electrical conductivity, current-voltage characteristics, (de)polarization currents and thermoelectric power have been measured under various experimental conditions. The measurements have been performed at temperatures between 20 and 550 °C with frequencies from 102 to 104 Hz and applied voltages from 1 to 103 V. For low voltages, the I–V characteristics are in good agreement with Ohmʹs law, while for higher voltages the dependence I ~ V1.2 is followed. The d.c. electrical conductivity has an activation energy lower in the ferroelectric phase and higher in the paraelectric phase. The frequency dependence of the a.c. conductivity follows the formula σ(ω) ~ ωs with s = 0.8. The depolarization current decreases according to the relation Id(t) ~ t−s.