Microstructure and phase transition of MnO2-doped bismuth layered-structure ferroelectrics

Md Saidul Islam, Jun Kano, Shinya Tsukada, Qingrui Yin, Seiji Kojima

Research output: Contribution to journalArticle

5 Citations (Scopus)

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 languageEnglish
JournalJapanese Journal of Applied Physics
Volume48
Issue number9 Part 2
DOIs
Publication statusPublished - 2009
Externally publishedYes

Fingerprint

Bismuth
bismuth
Ferroelectric materials
Phase transitions
Doping (additives)
microstructure
Microstructure
Permittivity
covalence
permittivity
Ferroelectric ceramics
Curie-Weiss law
Dielectric losses
Curie temperature
dielectric loss
softening
Activation energy
Crystal structure
ceramics
activation energy

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 journalArticle

Islam, Md Saidul ; Kano, Jun ; Tsukada, Shinya ; Yin, Qingrui ; Kojima, Seiji. / Microstructure and phase transition of MnO2-doped bismuth layered-structure ferroelectrics. In: Japanese Journal of Applied Physics. 2009 ; Vol. 48, No. 9 Part 2.
@article{a191166a164c4afe91185640cd6cb26e,
title = "Microstructure and phase transition of MnO2-doped bismuth layered-structure ferroelectrics",
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.",
author = "Islam, {Md Saidul} and Jun Kano and Shinya Tsukada and Qingrui Yin and Seiji Kojima",
year = "2009",
doi = "10.1143/JJAP.48.09KC10",
language = "English",
volume = "48",
journal = "Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes",
issn = "0021-4922",
publisher = "INSTITUTE OF PURE AND APPLIED PHYSICS",
number = "9 Part 2",

}

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 -