Flux growth and characterization of the relaxer-based Pb[(Zn1/3Nb2/3)(1-x)Ti-x]O-3 [PZNT] piezocrystals

Relaxer ferroelectric-based single crystals (1 - x)Pb(Zn1/3Nb2/3)O-3-xPbTiO (3) [PZNT] (x = 0 and 0.09) were grown from high temperature solutions, usi ng PbO or PbO/deltaB(2)O(3) as flux. The optimum flux compositions and conc entrations were found to be 50 wt.% PbO and (49 wt.% PbO + 1 wt.% B2O3). It has been shown that addition of up to 1 wt.% B2O3 can stabilize the perovs kite phase and improve the effectiveness of the flux. The optimum thermal p rofile consists of a soaking temperature at 1100 degreesC and a gradually i ncreasing cooling rate from 2 to 5 degreesC min(-1). The spontaneous nuclea tion process could be significantly modified by top-seeding technique. The crystal morphology was studied and related to a layer growth mechanism cont rolled by two-dimensional growth, and to the formation of pyramidal growth sectors. The phase analysis, the morphotropic domain structures and phase t ransitions, and the dielectric properties of the grown PZNT crystals were c haracterized by X-ray powder diffraction, polarized light microscopy and di electric spectroscopy. (C) 2000 Elsevier Science S.A. All rights reserved.