Li self-diffusion and ion conductivity in congruent 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LiNbO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>
 and 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LiTaO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>
 single crystals

Kofahl, Claudia; Dörrer, Lars; Muscutt, Brendan; Sanna, Simone; Hurskyy, Stepan; Yakhnevych, U.; Suhak, Yuriy; Fritze, Holger; Ganschow, Steffen; Schmidt, Harald

doi:10.1103/physrevmaterials.7.033403

Cited by 13 publications

(7 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also shown in Figure are the Li tracer diffusivities in congruent LiNbO 3, , which are lower by 3 orders of magnitude than the hydrogen diffusivities at 600 °C. At lower temperatures, this difference increases due to the higher activation energy of Li diffusion of 1.35 eV.…”

Section: Resultsmentioning

confidence: 89%

“…The straight line corresponds to a fit of the LiNbO 3 data to eq . Also shown are Li diffusivities of LiNbO 3 termed [Kofahl2023], which are adapted with permission from ref . Copyrighted by the American Physical Society.…”

Section: Resultsmentioning

confidence: 99%

“…At lower temperatures, this difference increases due to the higher activation energy of Li diffusion of 1.35 eV. Li diffuses via a vacancy mechanism dominated by structural vacancies in the congruent structure …”

Section: Resultsmentioning

confidence: 99%

“…In the literature, it was further shown that raising the hydrogen content in a sample up to 5 × 10 19 cm –3 leads to a substantial increase of conductivity . On the other hand, it was recently shown that Li migration can be the dominating contribution to the conductivity at temperatures down to 100 °C. − In order to clarify this discrepancy, we investigated H diffusion in Li 2 O-deficient (congruent) LiNbO 3 , LiTaO 3 , and LiNb 0.15 Ta 0.85 O 3 single crystals. The LiNbO 3 and LiTaO 3 crystals used in this study and the crystals used for Li diffusion experiments , were delivered by the same supplier.…”

Section: Introductionmentioning

confidence: 94%

“…On the other hand, it was recently shown that Li migration can be the dominating contribution to the conductivity at temperatures down to 100 °C. − In order to clarify this discrepancy, we investigated H diffusion in Li 2 O-deficient (congruent) LiNbO 3 , LiTaO 3 , and LiNb 0.15 Ta 0.85 O 3 single crystals. The LiNbO 3 and LiTaO 3 crystals used in this study and the crystals used for Li diffusion experiments , were delivered by the same supplier. This allows a direct comparison of the diffusion behavior and the contribution of the two species to conductivity.…”

Section: Introductionmentioning

confidence: 98%

See 4 more Smart Citations

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Kofahl,

Dörrer,

Wulfmeier

et al. 2024

Chem. Mater.

Self Cite

View full text Add to dashboard Cite

Hydrogen is an impurity that is incorporated into LiNb 1−x Ta x O 3 crystals during crystal growth or during thermal treatment in a humid atmosphere and may influence the physical properties in different ways. In this context, diffusion of hydrogen is an important process because it may enhance the ion conductivity of the material. We investigated the diffusion of hydrogen in LiNbO 3 , LiTaO 3 , and LiNb 0.15 Ta 0.85 O 3 single crystals in the temperature range between 311 and 606 °C using deuterium from a gaseous D 2 O source as a tracer. Diffusivities were determined by analyzing the relative deuterium fraction in the crystal with infrared spectroscopy or secondary ion mass spectrometry. The results are in good agreement with each other. The diffusivities in LiNbO 3 can be described by the Arrhenius law with an activation energy of 0.98 eV. The diffusivities in LiTaO 3 and LiNb 0.15 Ta 0.85 O 3 are nearly identical to those in LiNbO 3 within a maximum factor of 2. A direct interstitial diffusion mechanism is suggested where hydrogen migrates in the energy landscape of the crystal. From a comparison of the partial H and Li ion conductivities calculated from diffusivities to electrical conductivities measured by impedance spectroscopy, we conclude that hydrogen may contribute to the overall conductivity below 400 °C.

show abstract

Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 98%

See 3 more Smart Citations

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Kofahl,

Dörrer,

Wulfmeier

et al. 2024

Chem. Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

Oxygen Diffusion in Li(Nb,Ta)O₃ Single Crystals

Kofahl,

Uhlendorf,

Muscutt

et al. 2024

Physica Status Solidi (a)

View full text Add to dashboard Cite

Oxygen tracer self‐diffusion in LiNbO3, LiTaO3, and LiNb0.15Ta0.85O3 single crystals between 880 and 1050 °C is investigated. 18O2 isotope‐exchanged samples are analyzed by secondary ion mass spectrometry. The diffusivities of each of the three different materials can be described by the Arrhenius law with an activation enthalpy of diffusion of about 3.2–3.5 eV. The diffusivities are highest for LiNbO3 and are lower by about one order of magnitude for LiNb0.15Ta0.85O3 and LiTaO3. The change of the pre‐exponential factor is identified as the reason for the difference in diffusivities. The experimental results are compared to defect formation energy calculations as given in literature and to energy barrier calculations for the diffusion of a single O vacancy as determined by nudged elastic band calculations based on density‐functional theory. An oxygen vacancy mechanism is suggested to govern diffusion. The difference in diffusivities is tentatively attributed to a different number of freely migrating vacancies, probably due to defect complex formation.

show abstract

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)

View full text Add to dashboard Cite

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.

show abstract

Li self-diffusion and ion conductivity in congruent LiNbO3 and LiTaO3 single crystals

Cited by 13 publications

References 52 publications

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Oxygen Diffusion in Li(Nb,Ta)O₃ Single Crystals

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

Contact Info

Product

Resources

About

Li self-diffusion and ion conductivity in congruent LiNbO3 and LiTaO3 single crystals

Cited by 13 publications

References 52 publications

Hydrogen Diffusion in Li(Nb,Ta)O3 Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Hydrogen Diffusion in Li(Nb,Ta)O3 Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Oxygen Diffusion in Li(Nb,Ta)O3 Single Crystals

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

Contact Info

Product

Resources

About

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Hydrogen Diffusion in Li(Nb,Ta)O₃ Single Crystals Probed by Infrared Spectroscopy and Secondary Ion Mass Spectrometry

Oxygen Diffusion in Li(Nb,Ta)O₃ Single Crystals

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