Relaxor behavior in sol-gel-derived BaZr(0.40)Ti(0.60)O3 thin films

In the present work, we have reported the phase transition behavior of sol-gel-derived BaZr0.4Ti0.6O3 (BZT40) thin films. The dielectric properties of these films were measured as a function of temperature in the frequency range of 1 kHz to 1 MHz. A broad dielectric anomaly coupled with the shift of dielectric maxima toward a higher temperature with increasing frequency indicates the relaxor-type behavior in the films. The index of relaxation (gamma) and the broadening parameter (Delta) were estimated from a linear fit of the modified Curie-Weiss law. The value of gammaapproximate to1.79 and Deltaapproximate to76 K indicates the strong relaxor nature of these films. A remarkably good fit to the Vogel-Fulcher relation further supports such a relaxor nature. The films showed good polarization hysteresis at a low temperature, though that slims down yet persists even above the dielectric maximum temperature (T-m), which is about 170 K. (C) 2003 American Institute of Physics.