| Title of Article |
Effects of sintering temperature on microstructure and giant dielectric properties of (V + Ta) coedoped TiO2 ceramics |
| Date of Acceptance |
13 July 2017 |
| Journal |
| Title of Journal |
Journal of Alloys and Compounds |
| Standard |
ISI |
| Institute of Journal |
elsevier |
| ISBN/ISSN |
|
| Volume |
2017 |
| Issue |
725 |
| Month |
18 July 2017 |
| Year of Publication |
2017 |
| Page |
310-317 |
| Abstract |
The influences of sintering temperature on the microstructure and giant dielectric properties of a new
co-doped TiO2 system, i.e., V and Ta co-doped TiO2, were investigated. The grain size of (V1/2Ta1/
2)0.01Ti0.99O2 ceramics was enlarged with increasing sintering temperature. Dense microstructure and
homogeneous dispersion of dopants were achieved in the ceramics sintered at 1400e1500 C for 5 h. The
dielectric permittivity in the frequency range 40e106 Hz of the (V1/2Ta1/2)0.01Ti0.99O2 ceramics significantly
increased with the mean grain size, while the dielectric loss tangent was reduced to 0.033 at
102 Hz. Furthermore, the high-temperature stability of the dielectric permittivity was improved with
increasing mean grain size. The electrically heterogeneous microstructure consisting of semiconducting
grains and insulating grain boundaries and/or surface layers was confirmed using impedance spectroscopy.
The conduction inside the semiconducting grains was attributed to electron hopping between
Ti4þ and Ti3þ, which was confirmed by X-ray photoelectron spectroscopy. Very high resistivity with a
large conduction activation energy of the insulating parts was suggested as the primary cause of the
giant dielectric permittivity with low loss tangent. |
| Keyword |
Rutile TiO2 Giant dielectric permittivity Impedance spectroscopy Ceramic microstructure X-ray photoelectron spectroscopy Grain size |
| Author |
|
| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
false |
| Part of thesis |
true |
| Attach file |
|
| Citation |
0
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Publication
Journal Publication
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