<abstract xmlns="http://www.w3.org/1999/xhtml">Lithium tantalate solid solution, Li3+5xTa1−xO4 was prepared by conventional solid-state reaction at 925 °C for 48 h. The XRD analysis confirmed that these materials crystallized in a monoclinic symmetry, space group C2/C and Z = 8, which was similar to the reported International Crystal Database (ICDD), No. 98-006-7675. The host structure, β-Li3TaO4 had a rock-salt structure with a cationic order of Li+:Ta5+ = 3:1 over the octahedral sites. A rather narrow subsolidus solution range, i.e. Li3+5xTa1−xO4 (0 ⩽ x ⩽ 0.059) was determined and the formation mechanism was proposed as a replacement of Ta5+ by excessive Li+, i.e. Ta5+ ↔ 5Li+. Both Scherrer and Williamson-Hall (W-H) methods indicated the average crystallite sizes in the range of 31 nm to 51 nm. Two secondary phases, Li4TaO4:5 and LiTaO3 were observed at x = 0.070 and x = −0:013, respectively. These materials were moderate lithium ionic conductors with the highest conductivity of ~2.5 × 10−3 Ω −1 ˙ cm−1 at x = 0, at 0 °C and 850 °C; the activation energies were found in the range of 0.63 eV to 0.68 eV.</abstract>

Lithium tantalate solid solution, Li3+5xTa1−xO4 was prepared by conventional solid-state reaction at 925 °C for 48 h. The XRD analysis confirmed that these materials crystallized in a monoclinic symmetry, space group C2/C and Z = 8, which was similar to the reported International Crystal Database (ICDD), No. 98-006-7675. The host structure, β-Li3TaO4 had a rock-salt structure with a cationic order of Li+:Ta5+ = 3:1 over the octahedral sites. A rather narrow subsolidus solution range, i.e. Li3+5xTa1−xO4 (0 ⩽ x ⩽ 0.059) was determined and the formation mechanism was proposed as a replacement of Ta5+ by excessive Li+, i.e. Ta5+ ↔ 5Li+. Both Scherrer and Williamson-Hall (W-H) methods indicated the average crystallite sizes in the range of 31 nm to 51 nm. Two secondary phases, Li4TaO4:5 and LiTaO3 were observed at x = 0.070 and x = −0:013, respectively. These materials were moderate lithium ionic conductors with the highest conductivity of ~2.5 × 10−3 Ω −1 ˙ cm−1 at x = 0, at 0 °C and 850 °C; the activation energies were found in the range of 0.63 eV to 0.68 eV.

Subsolidus solution and ionic conductivity of rock-salt structured Li3+5xTa1−xO4 electroceramics

Department of Chemistry, Faculty of Science

Department of Mechanical and Material Engineering, Lee Kong Chian Faculty of Engineering and Science

Department of Physics, Faculty of Science

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Subsolidus solution and ionic conductivity of rock-salt structured LiTaO electroceramics

Lithium tantalate solid solution, Li3+5xTa1−xO4 was prepared by conventional solid-state reaction at 925 °C for 48 h. The XRD analysis confirmed that these...

Subsolidus solution and ionic conductivity of rock-salt structured Li_3+5xTa_1−xO₄ electroceramics

Published Online: Dec 12, 2020

Page range: 465 - 474

Received: Nov 29, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2020-0047

Keywords
ionic conductivity, subsolidus solution, β-LiTaO, electrical properties

© 2020 S. Shari et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Subsolidus solution and ionic conductivity of rock-salt structured Li3+5xTa1−xO4 electroceramics

Published Online: Dec 12, 2020

Page range: 465 - 474

Received: Nov 29, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2020-0047

Keywordsionic conductivity, subsolidus solution, β-LiTaO, electrical properties

© 2020 S. Shari et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Subsolidus solution and ionic conductivity of rock-salt structured Li_3+5xTa_1−xO₄ electroceramics

Keywords
ionic conductivity, subsolidus solution, β-LiTaO, electrical properties