Diffused phase transition and relaxor behavior in Pb(Fe_(2/3)W_(1/3))O_3 thin films

摘要

The authors have synthesized Pb(Fe_(2/3)W_(1/3))O_3 thin films on Pt/Ti/SiO_2/Si(100) substrates utilizing chemical solution deposition method. The dielectric relaxation was studied as a function of temperature (100-300 K) and frequency (100 Hz-1 MHz). A broad range of dielectric maxima was found, which shifted towards higher temperature with increase in frequency. The relaxation indication coefficient (γ) and broadening parameter (Δ) were estimated from a linear fit of the modified Curie-Weiss law and were found to be 2.00 and 50 K, respectively; indicating strong relaxor behavior. A remarkably good fit to Vogel-Fulcher relationship further supports the relaxor nature of the films. The slim hysteresis loop at low temperature is indicative of ferroelectricity due to the growth of nanopolar regions.