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Environmentally friendly (1-x) Bi0.5Na0.5TiO3-xBaTiO3 (BNBT, BNBTx) as the representative of the piezoelectric ceramic material because of its excellent piezoelectric properties in the vicinity of the morphotropic phase boundary (Morphotropic Phase Boundary, MPB) caused a wide range of research interests . , Drawing on the idea of the traditional lead-based piezoelectric ceramic ceramic BNBT inherent in some of the shortcomings , its system modified to further improve its piezoelectric properties , and to lay the foundation for the practical applications , the main content and the results are as follows : MPB near BNBT ( the select component x 0.065 ) , based on the study of the structure and electrical properties of Mn ions doped before and after BNBT ceramics doped dielectric loss is greatly reduced , and the piezoelectric coefficient increased to 150 pC / N, the coupling coefficients kp of 0.33 2. in doped Mn BNBT basis , through the introduction of the Li ions , the preparation of ternary solid solution of ( 0.935 - x ) Bi0.5Na0.5TiO3 - 0.065BaTiO3 - xLi0.5Bi0.5TiO3 - 0.5% Mn (BNLBMT), a significant improvement in the sintering properties of the ceramic , and effectively reduce the sintering temperature , to obtain optimum piezoelectric properties in the x = 0.06 when the piezoelectric coefficient d33 reaches 172 pC / N , 33% KP polarized dielectric constant of 837, the loss tanĪ“ was 0.026 3 . studied Fe, La, Ce, Nb , etc. different valence and ionic radius of the A site and B site doping on BNLBMT0.06 ceramic structure , the ferroelectric , dielectric and piezoelectric properties and phase transition behavior of law , doped with 0.2 mol % La has the best overall performance , d33 of 184 pC / N , kp 0.32 , and tanĪ“ were 983 and 0.033 . 4 . found high electrostrictive coefficient can be obtained with the new lead-free system on the basis of the BNBT introduced having a quadrature phase structure of KNbO3 , KNbO3 0.02 and above , the sample showed a pure electrostrictive response at 4 kV / mm electric field under the strain of up to 0.08%, up from 0.0296 m4c 2 electrostrictive coefficient Q , significantly higher than the typical lead-based electroluminescent stretchable material of Pb (Mg1/3Nb2/3 ) O3 (Q ~~ 0.017 m4C-2), not only that, at room temperature to the range of 150 oC , the field -induced strain shows good temperature stability, and shows the potential application in the field of drive, and the accurate displacement control .
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