Ferroelectric ceramics: defects and dielectric relaxations

Elissalde, Catherine; Ravez, J.

doi:10.1039/b010117f

Cited by 253 publications

(146 citation statements)

References 71 publications

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“…No loss peak was observed in the ε'' spectra, characterizing a deviation from the dipolar response of the system, predicted by the Debye theory 22 . This feature indicates that the applied field interacts with the material not only through reorientation of the electric dipoles 9,10,23 , but also through the displacement of the charge carriers, in accordance with the hopping-type conduction proposed for BGO in this work.…”

Section: Dielectric Characterizationmentioning

confidence: 99%

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

2003

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Bi 4 Ge 3 O 12 (bismuth germanate -BGO) single crystals were produced by the Czochralski technique and their electrical and dielectric properties were investigated by impedance spectroscopy. The isothermal ac measurements were performed for temperatures from room temperature up to 750 °C, but only the data taken above 500 °C presented a complete semicircle in the complex impedance diagrams. Experimental data were fitted to a parallel RC equivalent circuit, and the electrical conductivity was obtained from the resistivity values. Conductivity values from 5.4 × 10 -9 to 4.3 × 10 -7 S/cm were found in the temperature range of 500 to 750 °C. This electrical conductivity is thermally activated, following the Arrhenius law with an apparent activation energy of (1.41 ± 0.04) eV. The dielectric properties of BGO single crystal were also studied for the same temperature interval. Permittivity values of 20 ± 2 for frequencies higher than 10 3 Hz and a low-frequency dispersion were observed. Both electric and dielectric behavior of BGO are typical of systems in which the conduction mechanism dominates the dielectric response.

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Section: Dielectric Characterizationmentioning

confidence: 99%

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

2003

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“…It is also interesting to note that many ferroelectric materials, such as thin films or bulk material, exhibit phase-transition relaxor behavior characteristics that appear mainly in oxygen octahedron families, i.e., in the perovskite-type structure and in the tungsten-bronze-type structure ͑TKWB͒. 6,7 Among the perovskite-type structure compounds, complex lead-based structures with two different cations in the same crystallographic site are particularly concerned. Well-known examples are lead magnesium niobate ͑PMN͒, lead zinc niobate ͑PZN͒, and their solid solutions with lead titanate ͑PT͒, which are the most widely studied relaxor materials.…”

Section: Introductionmentioning

confidence: 99%

Investigation of phase transition in ferroelectric Pb0.70Sr0.30TiO3 thin films

Leal

Leite

Longo

et al. 2004

Journal of Applied Physics

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We have carried out dielectric and Raman spectroscopy studies at the 298 -623 K temperature range in polycrystalline Pb 0.70 Sr 0.30 TiO 3 thin films grown by a soft chemical method. The diffuse phase-transition behavior of the thin films was observed by means of the dielectric constant versus temperature curves, which show a broad peak. Such behavior was confirmed later by Raman spectroscopy measurements up to 823 K, indicating that a diffuselike phase transition takes place at around 548 -573 K. The damping factor of the E(1TO) soft mode was calculated using the damped simple harmonic oscillator model. On the other hand, Raman modes persist above the tetragonal to cubic phase transition temperature although all optical modes should be Raman inactive. The origin of these modes was interpreted in terms of a breakdown of the microscopic local cubic symmetry by chemical disorder. The lack of a well-defined transition temperature and the presence of broad bands at some temperature interval above the ferroelectric-paraelectric phase-transition temperature suggested a diffuse nature of the phase transition. This result corroborates the dielectric constant versus temperature data, which showed a broad ferroelectric phase transition in this thin film.

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“…Additional complications arise in the impedance spectroscopy of ferroelectric materials in which domain walls can participate in the relaxation processes. 9 Therefore, interpretation of impedance spectra of a polycrystalline material in terms of the microstructure represents a complex problem. Finally, the correlation between atomic structure of grain boundaries and transport properties requires spatially resolved transport data.…”

Section: Introductionmentioning

confidence: 99%

Potential and Impedance Imaging of Polycrystalline BiFeO₃ Ceramics

Kalinin

Suchomel

Davies

et al. 2002

Journal of the American Ceramic Society

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Electrostatic-force-sensitive scanning probe microscopy (SPM) is used to investigate grain boundary behavior in polycrystalline BiFeO 3 ceramics. Scanning surface potential microscopy (SSPM) of a laterally biased sample exhibits potential drops due to resistive barriers at the grain boundaries. In this technique, the tips acts as a moving voltage probe detecting local variations of potential associated with the ohmic losses within the grains and at the grain boundaries. An approach for the quantification of grain boundary, grain interior, and contact resistivity from SSPM data is developed. Scanning impedance microscopy (SIM) is used to visualize capacitive barriers at the grain boundaries. In SIM, a dc-biased tip detects the variations of local potential induced by the lateral ac voltage applied to the sample. Unlike the traditional dc and ac transport measurement, both of these techniques are sensitive to the variation of local potential (SSPM) or local voltage oscillation amplitude and phase (SIM), rather than to current. Therefore, special attention is paid to the relationship between SSPM and SIM images and data obtained from traditional impedance spectroscopy and dc transport measurements. For BiFeO 3 ceramics excellent agreement between the local SIM measurements and impedance spectroscopy data are demonstrated.

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Ferroelectric ceramics: defects and dielectric relaxations

Cited by 253 publications

References 71 publications

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

Investigation of phase transition in ferroelectric Pb0.70Sr0.30TiO3 thin films

Potential and Impedance Imaging of Polycrystalline BiFeO₃ Ceramics

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Ferroelectric ceramics: defects and dielectric relaxations

Cited by 253 publications

References 71 publications

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy

Investigation of phase transition in ferroelectric Pb0.70Sr0.30TiO3 thin films

Potential and Impedance Imaging of Polycrystalline BiFeO3 Ceramics

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Resources

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Potential and Impedance Imaging of Polycrystalline BiFeO₃ Ceramics