Anisotropic polarization switching in tungsten bronze ferroelectrics in binary (Bi1/2Na1/2)Nb2O6-BaNb 2O6 system

Takayuki Watanabe, Jumpei Hayashi, Kaoru Miura

研究成果: Contribution to journalArticle査読

4 被引用数 (Scopus)

抄録

Randomly oriented (1-x)BaNb2O6-x(Bi 1/2Na1/2)Nb2O6 ceramics were prepared by conventional solid state sintering. The ceramics (0.2 ≤ x ≤ 0.7) sintered at 1250°C consisted of a single phase of a tungsten bronze structure, while the end-member materials did not crystallize into the tungsten bronze structure. The crystal systems of tungsten bronze phases were orthorhombic for 0.2 ≤ x ≤ 0.25 and tetragonal for 0.3 ≤ x ≤ 0.7. The temperatures for the maximum dielectric constant (Tm) measured for orthorhombic crystals were 300 and 190°C for x = 0.2 and 0.25, respectively, and showed no frequency dispersion. However, the Tm for tetragonal crystals was suppressed below 160°C and showed an obvious frequency dispersion. To evaluate the orientation of spontaneous polarization, (001)-and (hk0)-oriented fiber-textured ceramics were prepared for x = 0.2, 0.25, and 0.3 by slip casting under a strong magnetic field. Clear hysteresis loops of polarization-electric field were observed for (001)-oriented orthorhombic ceramics (x = 0.2 and 0.25) at room temperature, while the polarization induced in the (hk0)-oriented or tetragonal ceramics (x = 0.3) varied proportionally to the external electric field. It was concluded that the tungsten bronze crystals, (1-x)BaNb2O6-x(Bi 1/2Na1/2)Nb2O6 (x = 0.2 and 0.25), are ferroelectric at room temperature with the spontaneous polarization parallel to the c-axis.

本文言語英語
論文番号09MD12
ジャーナルJapanese Journal of Applied Physics
49
9 PART 2
DOI
出版ステータス出版済み - 9 1 2010
外部発表はい

All Science Journal Classification (ASJC) codes

  • 工学(全般)
  • 物理学および天文学(全般)

フィンガープリント

「Anisotropic polarization switching in tungsten bronze ferroelectrics in binary (Bi<sub>1/2</sub>Na<sub>1/2</sub>)Nb<sub>2</sub>O<sub>6</sub>-BaNb <sub>2</sub>O<sub>6</sub> system」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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