Growth and characterization of single crystalline lithium niobate-tantalate (Li(Nb,Ta)O3) solid solutions for high-temperature sensor and actuator applications
Final Report Abstract
The main objective of the joint research project is the development and characterization of high-temperature stable Li(Nb,Ta)O3 solid solutions that can be applied in sensing and actuating applications. The growth of Li(Nb,Ta)O3 single crystals was performed at IMT-RAS by the Czochralski technique. It was established that the growth process requires the substantially reduced pulling rate from the melt (down to 0.5 mm/h), comparing to pure LiNbO3 and LiTaO3, which resulted in sufficiently large, good-quality crystals with LiNb0.88Ta0.12O3 composition. The Curie temperature studies of the grown compounds of the above mentioned and other compositions reveal its approximately linear dependence on Ta-concentration. This finding is of practical importance, since it allows to estimate the Curie temperature of any given Li(Nb,Ta)O3 crystal, provided that its Nb/Ta ratio is known. Further, powder diffraction analysis reveals a linear increase in lattice parameter a and a decrease in lattice parameter c with increase of Ta content, yielding unit-cell parameters of a = 0.516 nm and c = 1.385 nm for LiNb0.88Ta0.12O3. Further, in order to determine the atomic transport mechanisms in Li(Nb,Ta)O3, a comprehensive study of the electrical conductivity as a function of temperature in air and as a function of oxygen partial pressure at 900 °C was performed at TUC. The temperaturedependent electrical conductivity shows similar behavior for all the studied samples up to about 650 °C. Above that temperature, the LiNbO3 and LiNb0.88Ta0.12O3 specimens show somewhat higher conductivity, compared with LiTaO3. Analysis of the ionic contributions to the bulk conductivity allows to conclude that the conduction of Li-ions via Li-vacancies plays a primary role in Li(Nb,Ta)O3 in the temperature range 400-900 °C, while the impact of oxygen and niobium (tantalum) ions is insignificant. Further, the study of the conductivity as a function of oxygen partial pressure shows that LiNbO3 and the Nb-rich LiNb0.88Ta0.12O3 sample exhibit considerably higher conductivity at low oxygen partial pressure values when compared to the LiTaO3 specimen. In the case of LiTaO3, its conductivity remains unaffected by pO2 down to 10^−9 bar, with only a slight increase observed below this pressure. In contrast, a strong oxygen partial pressure dependent conductivity is observed for LiNbO3 and LiNb0.88Ta0.12O3 below about 10^−3 bar, suggesting that Nb-rich crystals can be reduced much more easily. Further, resonant piezoelectric spectroscopy was employed to investigate acoustic losses in Li(Nb,Ta)O3 resonators operated in the thickness-shear mode. The loss behavior of LiNb0.88Ta0.12O3 sample show a nearly constant Q^-1 value at relatively low temperatures, followed by a rapid increase above about 450 °C. This high-temperature loss increase is attributed to the piezoelectric/carrier relaxation mechanism. Comparison with congruent LN resonators highlights substantially lower losses in LiNb0.88Ta0.12O3.
Publications
-
Advanced ferroelectric LiNb(1-x)TaxO3 crystal: Crystal growth, crystal structure, physical properties, Armenian Journal of Physics 13 (2020) 235-242.
D. Roshchupkin, E. Emelin, O. Plotitcyna, R. Fahrtdinov, D. Irzhak, V. Karandashev, T. Orlova, B. Redkin, H. Fritze & Yu Suhak
-
Electrical and electromechanical properties of single crystalline Li(Nb,Ta)O3 solid solutions for high-temperature actuator applications, Proc. SMSI 2020 (2020) 57-58.
Y. Suhak, B. Jerliu, S. Ganschow, D. Roshchupkin, B. Red'kin, S. Sanna & H. Fritze
-
Single crystals of ferroelectric lithium niobate–tantalate LiNb1–x Ta x O3 solid solutions for high-temperature sensor and actuator applications. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, 76(6), 1071-1076.
Roshchupkin, Dmitry; Emelin, Evgenii; Plotitcyna, Olga; Rashid, Fahrtdinov; Irzhak, Dmitry; Karandashev, Vasilii; Orlova, Tatiana; Targonskaya, Natalya; Sakharov, Sergey; Mololkin, Anatolii; Redkin, Boris; Fritze, Holger; Suhak, Yuri; Kovalev, Dmitry; Vadilonga, Simone; Ortega, Luc & Leitenberger, Wolfram
-
Correlation of Electrical Properties and Acoustic Loss in Single Crystalline Lithium Niobate-Tantalate Solid Solutions at Elevated Temperatures. Crystals, 11(4), 398.
Suhak, Yuriy; Roshchupkin, Dmitry; Redkin, Boris; Kabir, Ahsanul; Jerliu, Bujar; Ganschow, Steffen & Fritze, Holger
-
Evaluation of similarities and differences of LiTaO3 and LiNbO3 based on high-T-conductivity, nonlinear optical fs-spectroscopy and ab initio modeling of polaronic structures. New Journal of Physics, 23(3), 033016.
Krampf, A.; Imlau, M.; Suhak, Y.; Fritze, H. & Sanna, S.
-
Oxygen Partial Pressure Dependent Electrical Conductivity of LiNb1−xTaxO3 Solid Solutions, Proc. SMSI 2021 (2021) 47-48.
Y. Suhak, A. Kabir, D. Roshchupkin, B. Red’kin, S. Ganschow & H. Fritze
-
Growth of ferroelectric lithium niobate-tantalate LiNb(1-x)TaxO3 crystals. Journal of Crystal Growth, 621, 127377.
Roshchupkin, D.; Fakhrtdinov, R.; Redkin, B.; Karandashev, V.; Khvostikov, V.; Mololkin, A.; Siminko, O. & Zabelin, A.
-
Li self-diffusion and ion conductivity in congruent LiNbO3 and LiTaO3 single crystals. Physical Review Materials, 7(3).
Kofahl, Claudia; Dörrer, Lars; Muscutt, Brendan; Sanna, Simone; Hurskyy, Stepan; Yakhnevych, Uliana; Suhak, Yuriy; Fritze, Holger; Ganschow, Steffen & Schmidt, Harald
