ABSTRACT Ferroelectric 1 mol.% La3+ and 0.5 mol.% Fe3+ codoped Pb[Zr0.54Ti0.46]O3 ceramics were studied by means of multifrequency electron paramagnetic resonance (EPR) spectroscopy. The obtained results prove that iron is incorporated at the [Zr,Ti]-site, acting as an acceptor and building a charged (Fe′Zr,Ti - VO· ·)· defect dipole with a directly coordinated oxygen vacancy for partial charge compensation. This feature of the defect associates has hitherto been identified only in hard, exclusively Fe3+-doped PZT compounds. The present results show, however, that a similar defect association of the Fe3+ functional center with a VO·· also exists in soft, donor-acceptor (La3+,Fe3+)-codoped PZT.
According to models developed by Arlt et al. electric dipoles from defect associates, such as the (Fe′Zr,Ti - VO··)· defect associate, which may give rise to an internal bias field that is discussed being responsible for ferroelectric aging.
Digital Object Identifier 10.1109/TUFFC.2008.757
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