Piezoelectric anomalies at the ferroelastic phase transitions of lead-free tungsten bronze ferroelectrics

Takayuki Watanabe, Jumpei Hayashi, Takanori Matsuda, Toshihiro Ifuku, Bong Yeon Lee, Takashi Iijima, Hiroshi Funakubo, Houzhona Yu, Nobuhiro Kumada

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


This paper reports on the piezoelectric anomalies at the temperature or composition-induced ferroelastic phase transitions of tungsten bronze ferroelectrics. First, the temperature-dependent piezoelectric properties of Sr1.9Ca0.1NaNb5O15 (SCNN) ceramics were characterized using a resonance/anti-resonance method. SCNN has a ferroelastic phase transition manifested by a broad dielectric peak in the temperature range of -60°C to 20°C. The electromechanical coupling factor and elastic compliance showed the maximum at -40°C, increasing the transverse piezoelectric constant (d31) by 38% compared with the room temperature value. Tungsten bronze ferroelectrics follow a trade-off relationship between the longitudinal piezoelectric constant (d33) and the Curie temperature, while SCNN deviates significantly from the trend curve. This deviation is attributed to the ferroelastic phase transition close to room temperature. Second, the ferroelastic phase transition was investigated for epitaxial films of (1-x)(Sr3Ba2)Nb10O 30-xBa4Bi2/3Nb10O30 as a function of the composition. A careful structural analysis by X-ray diffraction revealed that there is a ferroelastic phase boundary between tetragonal and orthorhombic crystals at x = 0.06-0.3. The electric field-induced strain and the relative dielectric constants characterized at 80K for the epitaxial films increased in the vicinity of the phase boundary composition. These results suggest that engineering the ferroelastic phase transition is an approach to improving the piezoelectric properties of lead-free tungsten bronze ferroelectrics.

Original languageEnglish
Pages (from-to)717-721
Number of pages5
JournalJournal of the Ceramic Society of Japan
Issue number1380
Publication statusPublished - Aug 2010
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • General Chemistry
  • Condensed Matter Physics
  • Materials Chemistry


Dive into the research topics of 'Piezoelectric anomalies at the ferroelastic phase transitions of lead-free tungsten bronze ferroelectrics'. Together they form a unique fingerprint.

Cite this