Effects of BaO on the structure and electrical properties of 0.95K0.5Na0.5(Nb0.94Sb0.06)O3-0.05LiTaO3lead-free ceramics

Dunmin Lin, Kin Wing Kwok, H. L.W. Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)

Abstract

Lead-free ceramics 0.95K0.5Na0.5(Nb0.94Sb0.06)O3-0.05 LiTaO3+ xmol%BaO (0 ≤ x ≤ 3.00) have been fabricated by an ordinary sintering technique. The results of x-ray diffraction show that the ceramic with a perovskite structure changes from tetragonal phase to pseudocubic phase by increasing the doping level of Ba, and the ceramics with 1.00 < x < 1.50 contain both the tetragonal and the pseudocubic phases at room temperature. After the doping with Ba, the grain growth is inhibited, the ferroelectric-paraelectric phase transition temperature (Tc) is decreased, and a diffuse phase transition is induced. The ferroelectric properties (Prand Ec) show a slight decrease with increasing x up to 1.25, and then become weakened significantly. Because of the coexistence of the tetragonal and pseudocubic phases, the piezoelectric and dielectric properties of the ceramics with 1.00 < x < 1.50 are enhanced significantly. The ceramic with x = 1.25 exhibits the optimum properties: d33= 261 pC N-1, kP= 0.52, kt= 0.46, εr= 1503, tan δ = 2.5% and Tc= 314 °C. Our results have also demonstrated that the ceramics are non-deliquescent.
Original languageEnglish
Pages (from-to)6778-6783
Number of pages6
JournalJournal of Physics D: Applied Physics
Volume40
Issue number21
DOIs
Publication statusPublished - 7 Nov 2007

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

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