IAM - Ceramic Materials and Technologies

Characterization of (Fe'Zr:Ti - VO'')' Defect Dipoles in (La,Fe)-Codoped PZT 52.5/47.5 Piezoelectric Ceramics by Multifrequency Electron Paramagnetic Resonance Spectroscopy

  • Author:

    Erdem, E; Eichel, R-A; Kungl, H; Hoffmann, M J; Ozarowski, A; van Tol, J; Brunel, LC

  • Source:

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, 2008, Band 55, Heft 5, S. 1061-1068

Abstract

Ferroelectric 1 mol.% La3+ and 0.15 mol.% Fe3+ codoped Pb[Zr0.54Ti0.46]O-3 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) - V-O 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 V-O(center dot center dot) 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) - V-O defect associate, which may give rise to an internal bias field that is discussed being responsible for ferroelectric aging.