Effects Of Doping Modification On Structure And Properties Of Bi₃TiNbO₉ Based Lead-free Piezoelectric Ceramics

In this paper,the Bi₃TiNbO₉-based lead-free piezoelectric ceramics were obtained by the conventional solid-state.The effects of the types,ways and content of doped ions on the crystal structure,microstructure,piezoelectricity and dielectric properties of ceramics were studied;and the process modification was also studied.The crystal structures,microstructure,piezoelectricity and dielectric properties of Bi₃TiNbO₉-x wt%CeO₂,Bi_3-xCe_xTiNbO_9+?and Bi₃Ti_1-xCe_xNbO₉ ceramics of CeO₂in different ways were studied.The XRD,SEM and Raman spectra confirmed that all the ceramics were typical bismuth-layer flake structure,which are obtained by doping CeO₂ in different ways:The vibration modes of the[TiO₆]octahedron all changed and did not change the vibrational modes of the Bi ions both in the A-site in the perovskite and in the?Bi₂O₂?²⁺in Bi₃Ti_1-xCe_xNbO₉ ceramics,which effectively improves the piezoelectric performance.The effects of bismuth oxide content,ion doping content and calcination temperatures on the crystal structure,microstructure,piezoelectricity and dielectric properties of Bi₃Ti_1-xCe_xNbO₉ ceramics were investigated.XRD and SEM showed that the anisotropy of the bismuth-layer structure after doping was obvious;the Bi₃Ti_0.0975Ce_0.025NbO₉ ceramic showed better electrical properties with excess 1%bismuth oxide,a calcination temperature of 800°C,and a sintering temperature of1050°C:d₃₃=18 pC/N,?_r=124,?=7.65 g/cm³,tan?=0.3%,k_p=7.4%,Q_m=2744.At the same time,the effect of Sr²⁺/Ce⁴⁺?Ba²⁺/W⁶⁺?Mg²⁺/Nb⁵⁺doping on the crystal structure,microstructure and electrical properties of Bi₃TiNbO₉ ceramics was analyzed.The results show that the doping of different ions have a significant effect on the synthesis temperature,sintering temperature,electrical conductivity and voltage resistance.