Electromechanical properties and charge transport of Ca3TaGa3Si2O14 (CTGS) single crystals at elevated temperatures

Suhak, Yuriy; Schulz, Michał; Johnson, Ward L.; Сотников, А. В.; Schmidt, H.; Fritze, Holger

doi:10.1016/j.ssi.2018.01.032

Cited by 20 publications

(17 citation statements)

References 24 publications

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“…Therefore, a one-dimensional physical model, as described in [68], is used to model the impedance spectra that are fitted to the related experimental data. The fit procedure results in reasonable values of the physical properties, such as elastic constants and effective viscosity, as published in [73], thereby confirming the validity of the fit approach. Another point is that the change in mass results from a change in density of the CZO film.…”

Section: Experimental Methodssupporting

confidence: 78%

“…Such resonators exhibit nearly unchanged resonance behavior at least after more than one year of uninterrupted operation at 1000 • C in air. In particular, the resonance frequency shows a relative shift of only 0.4 % during this period [73]. Moreover, the defect chemistry and options for miniaturization of these resonators are known [69,74,75].…”

Section: Experimental Methodsmentioning

confidence: 99%

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Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

et al. 2021

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Bulk ceria-zirconia solid solutions (Ce1−xZrxO2−δ, CZO) are highly suited for application as oxygen storage materials in automotive three-way catalytic converters (TWC) due to the high levels of achievable oxygen non-stoichiometry δ. In thin film CZO, the oxygen storage properties are expected to be further enhanced. The present study addresses this aspect. CZO thin films with 0 ≤ x ≤ 1 were investigated. A unique nano-thermogravimetric method for thin films that is based on the resonant nanobalance approach for high-temperature characterization of oxygen non-stoichiometry in CZO was implemented. The high-temperature electrical conductivity and the non-stoichiometry δ of CZO were measured under oxygen partial pressures pO2 in the range of 10−24–0.2 bar. Markedly enhanced reducibility and electronic conductivity of CeO2-ZrO2 as compared to CeO2−δ and ZrO2 were observed. A comparison of temperature- and pO2-dependences of the non-stoichiometry of thin films with literature data for bulk Ce1−xZrxO2−δ shows enhanced reducibility in the former. The maximum conductivity was found for Ce0.8Zr0.2O2−δ, whereas Ce0.5Zr0.5O2-δ showed the highest non-stoichiometry, yielding δ = 0.16 at 900 °C and pO2 of 10−14 bar. The defect interactions in Ce1−xZrxO2−δ are analyzed in the framework of defect models for ceria and zirconia.

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Section: Experimental Methodssupporting

confidence: 78%

Section: Experimental Methodsmentioning

confidence: 99%

Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

et al. 2021

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“…To date, such resonant microbalances lacked the required combination of sufficiently high resonator quality factors and stable electrodes at elevated temperatures to enable meaningful measurements. For example, La 3 Ga 5 SiO 14 (LGS) shows relatively low quality factors compared to Ca 3 TaGa 3 Si 2 O 14 (CTGS), 7 making temperature compensation more difficult. In this work, we demonstrate the ability to compensate for such temperature fluctuations, thereby enabling operation even at temperatures above 1000 C and the ability, for example in this work, to detect oxygen stoichiometry changes in the thin film model praseodymium-cerium oxide solid solution system, Pr x Ce 1-x O 2-d , (PCO) at 700 C.…”

mentioning

confidence: 99%

“…The details were published previously. 7,17 The temperature was measured in the vicinity of the resonator using a type B Pt/ Rh thermocouple. In order to determine mass changes, the electrical impedance of the resonators was measured in the vicinity of their resonance frequencies with a high-speed network analyzer (E5100A, Agilent, Santa Clara, USA).…”

mentioning

confidence: 99%

“…with the effective resonator area A and the mass sensitivity S ¼ 2f 2 TC = ffiffiffiffiffiffiffiffi ffi c 66 q p : The elastic constant c 66 and the density q of the resonator materials for LGS and CTGS are taken from previous publications. 7,17,19 If the temperature compensation is performed by simultaneous evaluation of the fundamental mode and the third overtone, a modified Sauerbrey equation is used. 18 Initially, the resonators of the microbalance were coated by PCO on one side only.…”

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confidence: 99%

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Thin-film nano-thermogravimetry applied to praseodymium-cerium oxide films at high temperatures

Schröder¹,

Fritze²,

Bishop

et al. 2018

Applied Physics Letters

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High precision measurements of oxygen nonstoichiometry d in thin film metal oxides M a O b6d at elevated temperatures and controlled oxygen partial pressures p O2 are reported with the aid of resonant microbalances. The resonant microbalances applied here consisted of y-cut langasite (La 3 Ga 5 SiO 14 ) and CTGS (Ca 3 TaGa 3 Si 2 O 14 ) piezoelectric resonators, operated in the thickness shear mode at $5 MHz. Measurements of variations in d of Pr 0.1 Ce 0.9 O 2-d (PCO) films are reported for the oxygen partial pressure range from 10 À8 bar to 0.2 bar at 700 C, and these results were found to be in good agreement with previously reported oxygen nonstoichiometry d data derived from chemical capacitance studies. The PCO thin-films were deposited via pulsed laser deposition on both sides of the resonators, whose series resonance frequency was tracked, converted into mass changes and, finally, into nonstoichiometry. The nonstoichiometry was observed to reach a plateau as the oxygen partial pressure dropped below about 10 À5 bar, the behavior being attributed to the full reduction of Pr to the trivalent state. These resonators enable stable operation up to temperatures above 1000 C, thereby maintaining high mass resolution suitable for determining oxygen nonstoichiometry variations in thin films deposited on such resonators. For the given experimental conditions, a mass resolution of $50 ng was achieved at 700 C with the CTGS resonator.

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Influence of Li‐Stoichiometry on Electrical and Acoustic Properties and Temperature Stability of Li(Nb,Ta)O₃ Solid Solutions up to 900 °C

Tichy‐Rács,

Hurskyy,

Yakhnevych

et al. 2024

Physica Status Solidi (a)

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The current work is focused on the impact of the lithium stoichiometry on electrical conductivity, acoustic properties, and high‐temperature stability of single crystalline Li(Nb,Ta)O3 at high temperatures. The crystals grown from Li‐deficient melts are treated by the vapor transport equilibration (VTE) method, achieving near stoichiometric Li‐content. It is shown that the VTE‐treated specimens generally exhibit lower conductivity at temperatures below 800 °C, which is attributed to the reduced number of Li‐vacancies in near stoichiometric Li(Nb,Ta)O3, provided that the Li‐ion migration dominates the conductivity in this temperature range. Further, it is shown that above 600–650 °C different mechanism increasingly contributes to the conductivity, which is consequently attributed to the electronic conduction. Further, it is shown that losses in LNT strongly increase above about 500 °C, which is interpreted to originate from conductivity‐related relaxation mechanism. Finally, the thermal stability of Li(Nb,Ta)O3 is evaluated by the measurement of the conductivity and resonance frequency as a function of time. It is found that during annealing at 700 °C for 350 h, the resonance frequency of LiNbO3 remains in a ± 100 ppm range of the initial value of 3.5 MHz.

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Electromechanical properties and charge transport of Ca3TaGa3Si2O14 (CTGS) single crystals at elevated temperatures

Cited by 20 publications

References 24 publications

Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

Thin-film nano-thermogravimetry applied to praseodymium-cerium oxide films at high temperatures

Influence of Li‐Stoichiometry on Electrical and Acoustic Properties and Temperature Stability of Li(Nb,Ta)O₃ Solid Solutions up to 900 °C

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Electromechanical properties and charge transport of Ca3TaGa3Si2O14 (CTGS) single crystals at elevated temperatures

Cited by 20 publications

References 24 publications

Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

Linking the Electrical Conductivity and Non-Stoichiometry of Thin Film Ce1−xZrxO2−δ by a Resonant Nanobalance Approach

Thin-film nano-thermogravimetry applied to praseodymium-cerium oxide films at high temperatures

Influence of Li‐Stoichiometry on Electrical and Acoustic Properties and Temperature Stability of Li(Nb,Ta)O3 Solid Solutions up to 900 °C

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Product

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Influence of Li‐Stoichiometry on Electrical and Acoustic Properties and Temperature Stability of Li(Nb,Ta)O₃ Solid Solutions up to 900 °C