Cargando…
Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics
Giant dielectric (GD) oxides exhibiting extremely large dielectric permittivities (ε’ > 10(4)) have been extensively studied because of their potential for use in passive electronic devices. However, the unacceptable loss tangents (tanδ) and temperature instability with respect to ε’ continue to...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8622824/ https://www.ncbi.nlm.nih.gov/pubmed/34834132 http://dx.doi.org/10.3390/molecules26227041 |
_version_ | 1784605784412258304 |
---|---|
author | Thanamoon, Noppakorn Chanlek, Narong Srepusharawoot, Pornjuk Swatsitang, Ekaphan Thongbai, Prasit |
author_facet | Thanamoon, Noppakorn Chanlek, Narong Srepusharawoot, Pornjuk Swatsitang, Ekaphan Thongbai, Prasit |
author_sort | Thanamoon, Noppakorn |
collection | PubMed |
description | Giant dielectric (GD) oxides exhibiting extremely large dielectric permittivities (ε’ > 10(4)) have been extensively studied because of their potential for use in passive electronic devices. However, the unacceptable loss tangents (tanδ) and temperature instability with respect to ε’ continue to be a significant hindrance to their development. In this study, a novel GD oxide, exhibiting an extremely large ε’ value of approximately 7.55 × 10(4) and an extremely low tanδ value of approximately 0.007 at 10(3) Hz, has been reported. These remarkable properties were attributed to the synthesis of a Lu(3+)/Nb(5+) co-doped TiO(2) (LuNTO) ceramic containing an appropriate co-dopant concentration. Furthermore, the variation in the ε’ values between the temperatures of −60 °C and 210 °C did not exceed ±15% of the reference value obtained at 25 °C. The effects of the grains, grain boundaries, and second phase particles on the dielectric properties were evaluated to determine the dielectric properties exhibited by LuNTO ceramics. A highly dense microstructure was obtained in the as-sintered ceramics. The existence of a LuNbTiO(6) microwave-dielectric phase was confirmed when the co-dopant concentration was increased to 1%, thereby affecting the dielectric behavior of the LuNTO ceramics. The excellent dielectric properties exhibited by the LuNTO ceramics were attributed to their inhomogeneous microstructure. The microstructure was composed of semiconducting grains, consisting of Ti(3+) ions formed by Nb(5+) dopant ions, alongside ultra-high-resistance grain boundaries. The effects of the semiconducting grains, insulating grain boundaries (GBs), and secondary microwave phase particles on the dielectric relaxations are explained based on their interfacial polarizations. The results suggest that a significant enhancement of the GB properties is the key toward improvement of the GD properties, while the presence of second phase particles may not always be effective. |
format | Online Article Text |
id | pubmed-8622824 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-86228242021-11-27 Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics Thanamoon, Noppakorn Chanlek, Narong Srepusharawoot, Pornjuk Swatsitang, Ekaphan Thongbai, Prasit Molecules Article Giant dielectric (GD) oxides exhibiting extremely large dielectric permittivities (ε’ > 10(4)) have been extensively studied because of their potential for use in passive electronic devices. However, the unacceptable loss tangents (tanδ) and temperature instability with respect to ε’ continue to be a significant hindrance to their development. In this study, a novel GD oxide, exhibiting an extremely large ε’ value of approximately 7.55 × 10(4) and an extremely low tanδ value of approximately 0.007 at 10(3) Hz, has been reported. These remarkable properties were attributed to the synthesis of a Lu(3+)/Nb(5+) co-doped TiO(2) (LuNTO) ceramic containing an appropriate co-dopant concentration. Furthermore, the variation in the ε’ values between the temperatures of −60 °C and 210 °C did not exceed ±15% of the reference value obtained at 25 °C. The effects of the grains, grain boundaries, and second phase particles on the dielectric properties were evaluated to determine the dielectric properties exhibited by LuNTO ceramics. A highly dense microstructure was obtained in the as-sintered ceramics. The existence of a LuNbTiO(6) microwave-dielectric phase was confirmed when the co-dopant concentration was increased to 1%, thereby affecting the dielectric behavior of the LuNTO ceramics. The excellent dielectric properties exhibited by the LuNTO ceramics were attributed to their inhomogeneous microstructure. The microstructure was composed of semiconducting grains, consisting of Ti(3+) ions formed by Nb(5+) dopant ions, alongside ultra-high-resistance grain boundaries. The effects of the semiconducting grains, insulating grain boundaries (GBs), and secondary microwave phase particles on the dielectric relaxations are explained based on their interfacial polarizations. The results suggest that a significant enhancement of the GB properties is the key toward improvement of the GD properties, while the presence of second phase particles may not always be effective. MDPI 2021-11-22 /pmc/articles/PMC8622824/ /pubmed/34834132 http://dx.doi.org/10.3390/molecules26227041 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Thanamoon, Noppakorn Chanlek, Narong Srepusharawoot, Pornjuk Swatsitang, Ekaphan Thongbai, Prasit Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title | Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title_full | Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title_fullStr | Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title_full_unstemmed | Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title_short | Microstructural Evolution and High-Performance Giant Dielectric Properties of Lu(3+)/Nb(5+) Co-Doped TiO(2) Ceramics |
title_sort | microstructural evolution and high-performance giant dielectric properties of lu(3+)/nb(5+) co-doped tio(2) ceramics |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8622824/ https://www.ncbi.nlm.nih.gov/pubmed/34834132 http://dx.doi.org/10.3390/molecules26227041 |
work_keys_str_mv | AT thanamoonnoppakorn microstructuralevolutionandhighperformancegiantdielectricpropertiesoflu3nb5codopedtio2ceramics AT chanleknarong microstructuralevolutionandhighperformancegiantdielectricpropertiesoflu3nb5codopedtio2ceramics AT srepusharawootpornjuk microstructuralevolutionandhighperformancegiantdielectricpropertiesoflu3nb5codopedtio2ceramics AT swatsitangekaphan microstructuralevolutionandhighperformancegiantdielectricpropertiesoflu3nb5codopedtio2ceramics AT thongbaiprasit microstructuralevolutionandhighperformancegiantdielectricpropertiesoflu3nb5codopedtio2ceramics |