Abstract
The effects of MnO2 doping on the microstructure and phase transition of ferroelectric CaBi4Ti4O15 (CBT) ceramics with x mol % of MnO2 (CBT-xM; x = 0;1;3) have been studied. The single-phase crystal structure and the plate-like grain morphology are clearly observed for all compositions, while extended grains are observed with x = 3. The dielectric permittivity and dielectric loss show that the Mn 2+ and Mn3+ ions are preferentially incorporated into the A- and B-sites, respectively, up to a limiting extent of approximately x = 2. The ac conductivity decreases and the activation energy increases with increasing Mn content owing to the decrease in the number of conducting carriers and increase in covalence, respectively. The Curie temperature TC is independent of MnO2 doping within the experimental accuracy, and the dielectric constant satisfies the Curie-Weiss law above TC. The temperature dependence of the soft mode with x = 0 and 1 shows a significant softening towards T1 ∼ TC + 113°C (at T 1, the square of the soft mode frequency ω2 s → 0). ω2 2 is approximately proportional to T - T1. These findings indicate that the displacive nature of the phase transition is not affected by MnO2 doping, at least below x = 3.
| Original language | English |
|---|---|
| Journal | Japanese Journal of Applied Physics |
| Volume | 48 |
| Issue number | 9 Part 2 |
| DOIs | |
| Publication status | Published - 2009 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Microstructure and phase transition of MnO2-doped bismuth layered-structure ferroelectrics. / Islam, Md Saidul; Kano, Jun; Tsukada, Shinya; Yin, Qingrui; Kojima, Seiji.
In: Japanese Journal of Applied Physics, Vol. 48, No. 9 Part 2, 2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Microstructure and phase transition of MnO2-doped bismuth layered-structure ferroelectrics
AU - Islam, Md Saidul
AU - Kano, Jun
AU - Tsukada, Shinya
AU - Yin, Qingrui
AU - Kojima, Seiji
PY - 2009
Y1 - 2009
N2 - The effects of MnO2 doping on the microstructure and phase transition of ferroelectric CaBi4Ti4O15 (CBT) ceramics with x mol % of MnO2 (CBT-xM; x = 0;1;3) have been studied. The single-phase crystal structure and the plate-like grain morphology are clearly observed for all compositions, while extended grains are observed with x = 3. The dielectric permittivity and dielectric loss show that the Mn 2+ and Mn3+ ions are preferentially incorporated into the A- and B-sites, respectively, up to a limiting extent of approximately x = 2. The ac conductivity decreases and the activation energy increases with increasing Mn content owing to the decrease in the number of conducting carriers and increase in covalence, respectively. The Curie temperature TC is independent of MnO2 doping within the experimental accuracy, and the dielectric constant satisfies the Curie-Weiss law above TC. The temperature dependence of the soft mode with x = 0 and 1 shows a significant softening towards T1 ∼ TC + 113°C (at T 1, the square of the soft mode frequency ω2 s → 0). ω2 2 is approximately proportional to T - T1. These findings indicate that the displacive nature of the phase transition is not affected by MnO2 doping, at least below x = 3.
AB - The effects of MnO2 doping on the microstructure and phase transition of ferroelectric CaBi4Ti4O15 (CBT) ceramics with x mol % of MnO2 (CBT-xM; x = 0;1;3) have been studied. The single-phase crystal structure and the plate-like grain morphology are clearly observed for all compositions, while extended grains are observed with x = 3. The dielectric permittivity and dielectric loss show that the Mn 2+ and Mn3+ ions are preferentially incorporated into the A- and B-sites, respectively, up to a limiting extent of approximately x = 2. The ac conductivity decreases and the activation energy increases with increasing Mn content owing to the decrease in the number of conducting carriers and increase in covalence, respectively. The Curie temperature TC is independent of MnO2 doping within the experimental accuracy, and the dielectric constant satisfies the Curie-Weiss law above TC. The temperature dependence of the soft mode with x = 0 and 1 shows a significant softening towards T1 ∼ TC + 113°C (at T 1, the square of the soft mode frequency ω2 s → 0). ω2 2 is approximately proportional to T - T1. These findings indicate that the displacive nature of the phase transition is not affected by MnO2 doping, at least below x = 3.
UR - http://www.scopus.com/inward/record.url?scp=77952724770&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952724770&partnerID=8YFLogxK
U2 - 10.1143/JJAP.48.09KC10
DO - 10.1143/JJAP.48.09KC10
M3 - Article
AN - SCOPUS:77952724770
VL - 48
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 9 Part 2
ER -