Re-entrant relaxor behavior in BaTiO3-Bi(Zn2/3Nb1/3)O3 ceramics

The (1-x)BaTiO3-xBi(Zn2/3Nb1/3)O-3 (x=0.10-0.25) ceramics were fabricated via solid-state reactions. Temperature-dependent polarization measurement reveals that with the temperature lowering, the remnant polarization increases till a maximum value before it decreases, showing a reentrant phenomenon. Absence of apparent switching current peaks in the current density as a function of electric field should indicate the lack of a ferroelectric transition, which is further verified by the consistent macroscopic phase structure from the Raman spectra. An anomalous peak in the full width at half maximum of a deconvoluted mode at similar to 515cm(-1) suggests the entering of a more disordered state of dipolar dynamics, which may be originated from the competition between the freezing of polar nanoregions and the random interacting fields.