Electrical properties of 0.98(K_0.5Na_0.5)NbO₃-0.02AETiO₃ piezoceramics doped with Li₂CO₃

Abstract

Ceramics with chemical compositions of 0.98(K_0.5Na_0.5)NbO₃-0.02AETiO₃ doped with 1.0 wt.% Li₂CO₃ (NKN-AET-Li, AE = Mg, Ca, Sr and Ba) were prepared by a convention ceramic processing. The crystal structures, microstructure and electrical properties of all ceramics were investigated. The results show that all the samples possess a perovskite structure. It was found that the orthorhombic to tetragonal polymorphic phase transition (PPT) temperature (T_O-T) shifted to near room temperature while maintaining a high Curie temperature T_c(≥400 °C) for NKN-CaT-Li and NKN-SrT-Li ceramics with high relative density (>96%). Piezoelectric values of NKN-CaT-Li and NKN-SrT-Li ceramics were found to be d₃₃ = 197 pC/N and d₃₃ = 243 pC/N; k_p = 0.32 and k_p = 0.34) near room temperature. The NKN-SrT-Li and NKN-CaT-Li ceramics showed good temperature stability of dielectric and piezoelectric properties within a temperature range of 50–200 °C.

Keywords:

• Powders solid state reaction
• piezoelectric properties
• perovskites

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Funded by: UGC New Delhi.