Effect of acceptor and donor dopants on polarization components of lead zirconate titanate thin films

Abstract

We have compared the magnitudes of reversible and irreversible polarization components of sol-gel-derived Nd- and Fe-doped PZT (53/47) thin films on platinized silicon substrates. Beyond the switching field, it was found that the reversible component of the polarization remains almost constant both for donor- (Nd) and acceptor- (Fe) doped PZT films. The irreversible polarization component reduces with the increase in Nd content, whereas it increases until 3 at.% Fe-doped PZT thin films. The dielectric behavior of these films at subswitching fields was analyzed in terms of Rayleigh law. The inverse of the Raleigh coefficient (U ) was considered as a measure of the obstacle for the domain-wall motion. In the case of Fe-doped PZT, the inverse of the Raleigh coefficient (U ) shows a declining linearity with Fe content, which may be found exactly opposite to that observed for Nd-doped PZT. The observed results are explained in terms of the nature of the defect-domain-wall interaction of acceptor-and-donor-doped PZT thin films. Studies indicated that in the case of Fe-doped PZT films, the possible defect interaction initiates only above 2 at.% and it was found to be much lower in magnitude in comparison with the Nd doping.