Electrical conductivity studies of iron doped Pb(Yb<inf>0.5</inf>Ta <inf>0.5</inf>)O<inf>3</inf> ceramics by impedance spectroscopy

The effect of iron substitution on the electrical properties of Pb(Yb 0.5Ta0.5)O3 (PYT) was studied by impedance spectroscopy in a wide temperature range. The interior grain contribution at high frequency and grain boundary contribution at low frequency to the total impedance were predominately seen in pure PYT. However, the grain boundary contribution gradually decreases with increasing iron concentration and for higher compositions; a space charge contribution at very low frequency was observed. The conductivity increased by one order with iron doping in the composition range studied and was attributed to the increase in grain size and the coexistence of Fe2+ and Fe3+ ions. © 2013 AIP Publishing LLC.