Temperature dependence of the dielectric constant and I.R. reflection spectrum of LiNBO3 by Raman scattering

Umarov, B. S.; Vetelino, J.F.; Abdullaev, N. S.; Anikiev, A. A.

doi:10.1016/0038-1098(80)90935-7

Cited by 6 publications

(2 citation statements)

References 8 publications

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“…A large increase in the dielectric constant around 600 K along the c-axis has been attributed to the ferroelectric property of the crystals. Ivanova et a1 (1978) and Umarov et a f (1980) have made Raman spectra and dielectric constant studies and observed that a strong increase in the dielectric constant around 600 K is consistent with the estimated static dielectric constant from the optical data using the Kramers-Kronig relation, but is not supported by the Lyddane-Sachs-Teller (LST) relation. At higher temperatures the conductivity of LiNb0, crystals increases and so does the dielectric constant, which may be due to the electrode barrier or other mechanisms which give rise to both Dcconduction and dielectric polarisation.…”

Section: Introductionmentioning

confidence: 93%

The AC conductivity and dielectric constant of lithium niobate single crystals

Mansingh

Dhar

1985

J. Phys. D: Appl. Phys.

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The AC conductivity sigma ( omega ) and dielectric constant epsilon ' of lithium niobate single crystals have been measured along the ferroelectric c-axis in the temperature range 77-700K and in the frequency region 0.1-100 kHz. At low temperatures, below 400K, the AC conductivity can be expressed as sigma ( omega )=A omega s, where the slope s is close to unity and decreases with increasing temperature. The dielectric constant in this temperature region shows a weak frequency and temperature dependence. At higher temperatures, above 400K, the AC conductivity shows a strong temperature dependence and weak frequency dependence. The dielectric constant in this region also shows a strong frequency dispersion. The mechanism of conduction in low and high temperature regions is discussed in the light of existing theoretical models.

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Section: Introductionmentioning

confidence: 93%

The AC conductivity and dielectric constant of lithium niobate single crystals

Mansingh

Dhar

1985

J. Phys. D: Appl. Phys.

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“…The dielectric permittivity also generally increases with temperature. Indeed, the thermal expansion of the crystalline structure allows for a more significant dielectric displacement, and thus a higher permittivity [32]. In addition, in a ferroelectric crystal such as lithium niobate, the dielectric dipoles become more mobile at higher temperatures and can better follow an external electric field, contributing to the dielectric permittivity.…”

Section: Resultsmentioning

confidence: 99%

Characterization of the Elastic, Piezoelectric, and Dielectric Properties of Lithium Niobate from 25 °C to 900 °C Using Electrochemical Impedance Spectroscopy Resonance Method

2022

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Lithium niobate (LiNbO3) is known for its high Curie temperature, making it an attractive candidate for high-temperature piezoelectric applications (>200 °C); however, the literature suffers from a paucity of reliable material properties data at high temperatures. This paper therefore provides a complete set of elastic and piezoelectric coefficients, as well as complex dielectric constants and the electrical conductivity, for congruent monocrystalline LiNbO3 from 25 °C to 900 °C at atmospheric pressure. An inverse approach using the electrochemical impedance spectroscopy (EIS) resonance method was used to determine the materials’ coefficients and constants. Single crystal Y-cut and Z-cut samples were used to estimate the twelve coefficients defining the electromechanical coupling of LiNbO3. We employed an analytical model inversion to calculate the coefficients based on a linear superposition of nine different bulk acoustic waves (three longitudinal waves and six shear waves), in addition to considering the thermal expansion of the crystal. The results are reported and compared with those of other studies for which the literature has available values. The dominant piezoelectric stress constant was found to be e15, which remained virtually constant between 25 °C and 600 °C; thereafter, it decreased by approximately 10% between 600 °C and 900 °C. The elastic stiffness coefficients c11E, c12E, and c33E all decreased as the temperature increased. The two dielectric constants ϵ11S and ϵ33S increased exponentially as a function of temperature.

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High temperature characterization of piezoelectric lithium niobate using electrochemical impedance spectroscopy resonance method

Castilla

Bélanger

Zednik

2017

Journal of Applied Physics

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Piezoelectric materials reversibly deform when exposed to an electric field. This property is indispensable to modern engineering devices, enabling a wide range of sensors and actuators. However, unfortunately conventional piezoelectric materials are limited to operating temperatures of below approximately 200 °C. Lithium niobate is a promising candidate for high temperature applications (above 500 °C), as it has a high Curie temperature (1200 °C) and good piezoelectric properties. Nevertheless, degradation mechanisms occurring at elevated temperatures are not fully understood, although they are known to interfere with the piezoelectric behavior. In addition, the material properties of this technologically promising ceramic have not been adequately characterized at high temperatures, particularly when excited at high frequencies, due to the difficulty of performing such measurements. We therefore employ an electrochemical impedance spectroscopy resonance method using a novel analytical model to determine the material properties of single crystal lithium niobate over the wide frequency range of 100 kHz to 7 MHz for temperatures up to 750 °C. We find that lithium niobate retains its good piezoelectric properties over this entire frequency and temperature range and rules out suspected degradation mechanisms involving ionic conductivity or vacancy diffusion.

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Temperature dependence of the dielectric constant and I.R. reflection spectrum of LiNBO3 by Raman scattering

Cited by 6 publications

References 8 publications

The AC conductivity and dielectric constant of lithium niobate single crystals

The AC conductivity and dielectric constant of lithium niobate single crystals

Characterization of the Elastic, Piezoelectric, and Dielectric Properties of Lithium Niobate from 25 °C to 900 °C Using Electrochemical Impedance Spectroscopy Resonance Method

High temperature characterization of piezoelectric lithium niobate using electrochemical impedance spectroscopy resonance method

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