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Title: Deaging of heat-treated iron-doped lead zirconate titanate ceramics

Abstract

Doping strongly influences the properties of ferroelectric perovskite materials. One striking difference between donor- and acceptor-doped materials is the transition from 'soft' to 'hard' ferroelectric behavior. The physical reasons for this phenomenon are still unclear. The authors present measurements of the ferroelectric hysteresis and deaging behavior of iron-doped lead zirconate titanate after adjusting the defect structure by heat treatment in an oxygen-depleted atmosphere. Contrary to expectations, the introduction of extra oxygen vacancies makes the material 'softer' .This effect, which is discussed based on a model of defect dipoles, sheds new light on the unsolved problem of hardening and aging.

Authors:
; ; ;  [1];  [2];  [3]
  1. Institute of Materials Science, TU Darmstadt, 64287 Darmstadt (Germany)
  2. (Turkey)
  3. (Germany)
Publication Date:
OSTI Identifier:
20880202
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 89; Journal Issue: 26; Other Information: DOI: 10.1063/1.2425035; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATMOSPHERES; CERAMICS; CRYSTALS; DIPOLES; DOPED MATERIALS; FERROELECTRIC MATERIALS; HARDENING; HEAT TREATMENTS; HYSTERESIS; IRON; OXYGEN; PEROVSKITE; PZT; VACANCIES

Citation Formats

Granzow, T., Suvaci, E., Kungl, H., Hoffmann, M. J., Department of Materials Science and Engineering, Anadolu University, 26480 Eskisehir, and Institute for Ceramics in Mechanical Engineering, Karlsruhe University, 76131 Karlsruhe. Deaging of heat-treated iron-doped lead zirconate titanate ceramics. United States: N. p., 2006. Web. doi:10.1063/1.2425035.
Granzow, T., Suvaci, E., Kungl, H., Hoffmann, M. J., Department of Materials Science and Engineering, Anadolu University, 26480 Eskisehir, & Institute for Ceramics in Mechanical Engineering, Karlsruhe University, 76131 Karlsruhe. Deaging of heat-treated iron-doped lead zirconate titanate ceramics. United States. doi:10.1063/1.2425035.
Granzow, T., Suvaci, E., Kungl, H., Hoffmann, M. J., Department of Materials Science and Engineering, Anadolu University, 26480 Eskisehir, and Institute for Ceramics in Mechanical Engineering, Karlsruhe University, 76131 Karlsruhe. Mon . "Deaging of heat-treated iron-doped lead zirconate titanate ceramics". United States. doi:10.1063/1.2425035.
@article{osti_20880202,
title = {Deaging of heat-treated iron-doped lead zirconate titanate ceramics},
author = {Granzow, T. and Suvaci, E. and Kungl, H. and Hoffmann, M. J. and Department of Materials Science and Engineering, Anadolu University, 26480 Eskisehir and Institute for Ceramics in Mechanical Engineering, Karlsruhe University, 76131 Karlsruhe},
abstractNote = {Doping strongly influences the properties of ferroelectric perovskite materials. One striking difference between donor- and acceptor-doped materials is the transition from 'soft' to 'hard' ferroelectric behavior. The physical reasons for this phenomenon are still unclear. The authors present measurements of the ferroelectric hysteresis and deaging behavior of iron-doped lead zirconate titanate after adjusting the defect structure by heat treatment in an oxygen-depleted atmosphere. Contrary to expectations, the introduction of extra oxygen vacancies makes the material 'softer' .This effect, which is discussed based on a model of defect dipoles, sheds new light on the unsolved problem of hardening and aging.},
doi = {10.1063/1.2425035},
journal = {Applied Physics Letters},
number = 26,
volume = 89,
place = {United States},
year = {Mon Dec 25 00:00:00 EST 2006},
month = {Mon Dec 25 00:00:00 EST 2006}
}
  • Highlights: • The multiferroic ceramics consisted of PFT and PZT. • Crystal structure changed from cubic to mixedcubic and tetragonal with increasing PZT content. • Dielectric showed the samples underwent a typical relaxor ferroelectric behavior. • Magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops. - Abstract: Multiferroic (1 − x)Pb(Fe{sub 0.5}Ta{sub 0.5})O{sub 3}–xPb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3} (or PFT–PZT) ceramics were synthesized by solid-state reaction method. The crystal structure and phase formation of the ceramics were examined by X-ray diffraction (XRD). The local structure surrounding Fe and Ti absorbing atoms was investigated by synchrotron X-ray Absorption Near-Edgemore » Structure (XANES) measurement. Dielectric properties were studied as a function of frequency and temperature using a LCR meter. A vibrating sample magnetometer (VSM) was used to determine the magnetic hysteresis loops. XRD study indicated that the crystal structure of the sample changed from pure cubic to mixed cubic and tetragonal with increasing PZT content. XANES measurements showed that the local structure surrounding Fe and Ti ions was similar. Dielectric study showed that the samples underwent a typical relaxor ferroelectric behavior while the magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops.« less
  • The effects of Cr[sub 2]O[sub 3] doping (0 to 0.6 wt%) on the microstructure and electrical properties of ternary Pb[sub 0.97]Sr[sub 0.93]-[Zr[sub 0.458]Ti[sub 0.452](Mn[sub 1/3]Nb[sub 2/3])[sub 0.09]]O[sub 3] piezoelectric ceramics have been studied. Abnormal grain growth (grain sizes of 2.8 to 28.5 [mu]m) and densification (porosities of 2% to 12%) are found, and the tetragonality c/a nearly keeps constant whereas c and a slightly decrease in the doping range. The results for the temperature dependence of electric conductivity and the dielectric constant show that electric conductivity increases continuously over 0.1 wt% content, activation energies are all close to 0.92 eVmore » in the paraelectric state, and the curie temperature [Tc] decreases with increasing doping content. Minor additives of [le]0.1 wt% improve the dielectric and piezoelectric properties, but with more additives of [ge]0.4 wt% electrical properties appear to deteriorate. Thus, these phenomena can be ascribed mainly to anomalous developed microstructure.« less
  • We have used resonance methods to determine the variation of all the independent piezoelectric, elastic, and dielectric material coefficients, as well as the corresponding electromechanical coupling factors, of soft and hard doped piezoelectric lead zirconate titanate (PZT) ceramics with compositions near the morphotropic phase boundary, as a function of temperature ranging between -165 and 195 degree sign C. The material coefficients were obtained by analyzing the fundamental resonance of the impedance or admittance spectra as a function of frequency for several sample resonance geometries. The piezoelectric coefficients d{sub 33}, -d{sub 31}, and d{sub 15}, as well as the dielectric permittivitymore » coefficients {epsilon}{sub 11}{sup T} and {epsilon}{sub 33}{sup T}, generally increased with temperature for both soft and hard PZT samples. However, the elastic compliance coefficients s{sub 11}{sup E}, -s{sub 12}{sup E}, s{sub 33}{sup E}, and s{sub 55}{sup E} exhibited abnormal variations seen as broad peaks over parts of the tested temperature range. Additionally, thermal hystereses were observed in all the studied material coefficients over the temperature cycle. Finally, it was noted that, overall, the material coefficients of soft PZT varied significantly more than those of hard PZT under changing temperature conditions.« less
  • Influence of uniaxial pressure (0-1000 bars) applied parallel to or perpendicularly to the ac or dc electric field (in one-dimensional or two-dimensional manner) on dielectric and ferroelectric properties of hard lead zirconate titanate (PZT) ceramics were investigated. The experimental results revealed that applying uniaxial pressure leads to a reduction in the peak intensity of the electric permittivity (epsilon), of the frequency dispersion as well as of the dielectric hysteresis. Moreover, with increasing pressure the peak intensity of epsilon becomes diffused and shifts to a higher temperature. It was also found that simultaneous application of uniaxial pressure and electric field (perpendicularmore » to each other) in the poling process improves the ferroelectric properties. This indeed indicates new possibility for poling materials with a high coercive field and/or high electric conductivity. The effects of uniaxial load are weaker than that obtained for soft PZT ceramics. It was concluded that applying uniaxial pressure induces similar effects as increasing the Ti ion concentration in PZT system. The obtained results were interpreted through Cochran soft mode and domain switching processes under applying of pressure.« less
  • The amount of 90 deg reorientation during poling was determined from mechanical strains measured during the poling process. With tetragonal lead titanate zirconate 53% of the possible 90 deg reorientation occurred during poling, but this figure dropped to 44% upon removal of the poling field. With barium titanate the figures are only 17 and 12%, respectively. Comparison of the polarization of poled polycrystalline barium titanate with that for single crystals indicates that 180 deg reorientation is virtually perfect. Application of very high compressive stress parallel to the polar axis causes 90 deg switching of nearly all aligned domains, and, therefore,more » removes virtually all polarlzation. Curves of released charge as function of mechanical strain are nearly linear, but curves of released charge as function of stress are strongly nonlinear. Application of high compressive stress perpendicular to the polar axis also causes 90 deg domain reorientation and a reduction in the total polarization of the ceramic. This domain reorientation may be interpreted as a shift of the polar axes of some domains into a position more closely corresponding to the plane of cross expansion, and typically the total electric moment is reduced by less than 10%. High electric stress causes 180 deg as well as 90 deg domain reorientation. With prepoled specimens dc fields in the same direction as the poling field cause 90 deg switching, while reverse dc fields cause both 90 and 180 deg reorientation with the latter predominating. (auth)« less