Atomistic configurational effects on piezoelectric properties of La 3Ta0.5Ga5.5O14 and a new piezoelectric crystal design

Chan Yeup Chung, Ritsuko Yaokawa, Hiroshi Mizuseki, Yoshiyuki Kawazoe

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Single crystalline langatate (LTG, La3Ta0.5Ga 5.5O14) has been widely used as a sensor material in high temperature applications because of its thermally stable piezoelectric properties. In this research, to elucidate the relationship between piezoelectric tensors and local ionic configurations, first-principles calculations based on density functional perturbation theory (DFPT) were performed on various local ionic structures. The results indicate that two independent relaxed-ion piezoelectric coefficients, e11 and e 14, increased with increases in La(3e )-O and Ta(1a)-O distances or decreases in Ga(3f,2d)-O distances. Thus, to obtain high piezoelectric constants in this crystal, ions larger than La3+ should be incorporated at 3e sites to open the distance between 3e ions and oxygen ions, and ions smaller than Ga3+ should be introduced at 2d and 3f sites to reduce the distance between Ga and O ions. Finally, from this design rule, a new crystal, BTAS (Ba 3TaAl3Si2O14), which belongs to the same P321 group, is proposed. The calculated relaxed-ion piezoelectric coefficient e11 of BTAS was 17.7% higher than the coefficient of a LTG crystal. This significant increase confirms BTAS as a useful new piezo-material, especially in applications where there is also a need to reduce the use of more expensive elements.

Original languageEnglish
Pages (from-to)6473-6479
Number of pages7
JournalActa Materialia
Volume59
Issue number16
DOIs
Publication statusPublished - 2011 Sep

Keywords

  • Crystal structure
  • Crystalline oxide
  • Density functional
  • First-principles electron theory
  • Piezoelectricity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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