Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties

The purpose of this work is to present a systematic study related to the doping mechanism, structural and electrical properties of the novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) system. The pyrochlores with the general formula of Bi3.36Fe2.08+xTa2.56-xO14.56-x (-0.32 ≤ x ≤ 0.48) were prepared...

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Main Authors: Jusoh, Farah Aishah, Tan, Kar Ban, Zainal, Zulkarnain, Chen, Soo Kien, Khaw, Chwin Chieh, Lee, Oon Jew
Format: Article
Language:English
Published: Elsevier 2020
Online Access:http://psasir.upm.edu.my/id/eprint/86926/
http://psasir.upm.edu.my/id/eprint/86926/1/Novel%20pyrochlores.pdf
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author Jusoh, Farah Aishah
Tan, Kar Ban
Zainal, Zulkarnain
Chen, Soo Kien
Khaw, Chwin Chieh
Lee, Oon Jew
author_facet Jusoh, Farah Aishah
Tan, Kar Ban
Zainal, Zulkarnain
Chen, Soo Kien
Khaw, Chwin Chieh
Lee, Oon Jew
author_sort Jusoh, Farah Aishah
building UPM Institutional Repository
collection Online Access
description The purpose of this work is to present a systematic study related to the doping mechanism, structural and electrical properties of the novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) system. The pyrochlores with the general formula of Bi3.36Fe2.08+xTa2.56-xO14.56-x (-0.32 ≤ x ≤ 0.48) were prepared through solid-state reaction at 975 °C for 48 h. The subsolidus solution formation involved a mechanism of x Ta5+ + x O2− ↔ x Fe3+. These phase-pure BFT pyrochlores had a cubic structure with a space group of Fd3m (No. 227), Z = 4. Their lattice parameters were found to vary insignificantly within the range 10.4979 (8)-10.5033 (1) Å. The crystallite sizes determined by Scherrer and Williamson–Hall methods showed a good agreement with their values found to be in the range ∼57−78 nm. Meanwhile, the larger grain sizes in the range 0.2−4.7 μm were measured by the scanning electron microscopy (SEM) analysis. BFT pyrochlores were also found to be high refractory and thermally stable by the thermal analyses. These highly insulating pyrochlores exhibited high activation energies, ∼0.87−1.10 eV; moderate high dielectric constants, ∼78–92 and dielectric losses, ∼10-1 at 1 MHz and ∼30 °C. As such, these dielectric materials could be attractive candidates for potential application in low temperature co-fired ceramic (LTCC).
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spelling upm-869262022-01-05T08:33:28Z http://psasir.upm.edu.my/id/eprint/86926/ Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties Jusoh, Farah Aishah Tan, Kar Ban Zainal, Zulkarnain Chen, Soo Kien Khaw, Chwin Chieh Lee, Oon Jew The purpose of this work is to present a systematic study related to the doping mechanism, structural and electrical properties of the novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) system. The pyrochlores with the general formula of Bi3.36Fe2.08+xTa2.56-xO14.56-x (-0.32 ≤ x ≤ 0.48) were prepared through solid-state reaction at 975 °C for 48 h. The subsolidus solution formation involved a mechanism of x Ta5+ + x O2− ↔ x Fe3+. These phase-pure BFT pyrochlores had a cubic structure with a space group of Fd3m (No. 227), Z = 4. Their lattice parameters were found to vary insignificantly within the range 10.4979 (8)-10.5033 (1) Å. The crystallite sizes determined by Scherrer and Williamson–Hall methods showed a good agreement with their values found to be in the range ∼57−78 nm. Meanwhile, the larger grain sizes in the range 0.2−4.7 μm were measured by the scanning electron microscopy (SEM) analysis. BFT pyrochlores were also found to be high refractory and thermally stable by the thermal analyses. These highly insulating pyrochlores exhibited high activation energies, ∼0.87−1.10 eV; moderate high dielectric constants, ∼78–92 and dielectric losses, ∼10-1 at 1 MHz and ∼30 °C. As such, these dielectric materials could be attractive candidates for potential application in low temperature co-fired ceramic (LTCC). Elsevier 2020-09 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/86926/1/Novel%20pyrochlores.pdf Jusoh, Farah Aishah and Tan, Kar Ban and Zainal, Zulkarnain and Chen, Soo Kien and Khaw, Chwin Chieh and Lee, Oon Jew (2020) Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties. Journal of Materials Research and Technology, 9 (5). 11022 - 11034. ISSN 2238-7854; ESSN: 2214-0697 https://www.sciencedirect.com/science/article/pii/S2238785420315982 10.1016/j.jmrt.2020.07.102
spellingShingle Jusoh, Farah Aishah
Tan, Kar Ban
Zainal, Zulkarnain
Chen, Soo Kien
Khaw, Chwin Chieh
Lee, Oon Jew
Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title_full Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title_fullStr Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title_full_unstemmed Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title_short Novel pyrochlores in the Bi2O3-Fe2O3-Ta2O5 (BFT) ternary system: synthesis, structural and electrical properties
title_sort novel pyrochlores in the bi2o3-fe2o3-ta2o5 (bft) ternary system: synthesis, structural and electrical properties
url http://psasir.upm.edu.my/id/eprint/86926/
http://psasir.upm.edu.my/id/eprint/86926/
http://psasir.upm.edu.my/id/eprint/86926/
http://psasir.upm.edu.my/id/eprint/86926/1/Novel%20pyrochlores.pdf