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Publication
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| Title of Article |
Origin of colossal dielectric performance of rutile-TiO2 by substitution with
Y3++Ta5+ dopants: DFT calculations and experimental study |
| Date of Acceptance |
19 April 2022 |
| Journal |
| Title of Journal |
Materialia |
| Standard |
SCOPUS |
| Institute of Journal |
elsevier |
| ISBN/ISSN |
2589-1529 |
| Volume |
2022 |
| Issue |
22 |
| Month |
May |
| Year of Publication |
2022 |
| Page |
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| Abstract |
Highly compacted microstructures of Y3++Ta5+ co-doped TiO2 (YTTO) ceramics were fabricated. The YTTO ceramics contain not only the rutile structure but also contains the secondary phase of the microwave dielectric
YTaTiO6 particles. The decrease in the mean grain size of the YTTO was attributed to the inhibited grain growth
due to the pinning effect of the YTaTiO6 phase particles. The YTTO can exhibit a colossal permittivity (𝜀ˊ ∼
8.5 × 104) and low dielectric loss (tan𝛿 ∼ 0.021). Moreover, the excellent temperature stability of 𝜀ˊ was found
to be less ±15% over a wide temperature range. The semiconducting and highly insulating parts in the YTTO
ceramics were proved using impedance spectroscopy. The reduction of Ti4+ to Ti3+ was partially existed due to
the substitution of donor Ta5+, leading to the semiconducting grains. The DFT calculation showed that the defect
structure of 𝐘3+
2 𝐕⋅⋅ 0𝐓i3+ was not preferable to create. Therefore, the electron-pinned defect-dipoles were theoretically predicted to be not formed. Instead, the interfacial polarization at the interface between semiconducting
grain and insulating grain boundary/microwave YTaTiO6 phase plays a primary role in the overall dielectric
properties. |
| Keyword |
Colossal permittivity, Interfacial polarization, First principle calculation, TiO2 |
| Author |
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| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
false |
| Part of thesis |
true |
| Attach file |
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| Citation |
0
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Journal Publication
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