Ceramics-Silikáty 55 (2) 134-139 (2011)

Influence of La in xPBBiN of ternary nanoceramic composite (1-x)0.5PMN-0.5PZT-xPBBiN system by mechanic al activatio n technique for dielectric and piezoelectric properties

K. Ramam, K. Chandramouli

(1-x)[0.5Pb(Mg_0.33Nb_0.67)O₃-0.5Pb(Zr_0.53Ti_0.47)O₃]-x[Pb_0.557Ba_0.38La_0.022Bi_0.02Nb₂O₆] with both perovskite and tungsten bronze structured composite have been synthesized through mechanical activation technique. The strong influence of lanthanum addition to the lead-barium-bismuth-niobate (xPBLBiN) ceramics in perovskite structured (1-x)PMN-PZT on structural and functional properties is confirmed. X-ray diffraction patterns studies showed that these complex composites consisted of perovskite Cubic with tungsten bronze Orthorhombic phases. La modification in PBBiN of a ternary system (1-x)PMN-PZTxPBBiN revealed intensified orthorhombicity. As La increased the dielectric and piezoelectric properties tremendously increased in (1-x)PMN-PZT-xPBLBiN nanoceramic composite. The optimum dielectric and piezoelectric properties (ε_RT = 2931, k_p = 0.461 and d₃₃ = 428 pC/N) were found in x =0.4 composite. We achieved novel nanocomposites synthesized by high energy ball milling method and having binary structures in a single composite with excellent functional properties that can be used for energy harvesting applications.

Keywords: Ferroelectrics; X-ray diffraction; Dielectric response; Mechanical Activation, Piezoelectricity