Polarization Switching Behavior of Ferroelectric (NH₄)_0.39K_0.61NO₃ Films

The polarization switching transients of spray-deposited ferroelectric (NH4)0.39K0.61NO3 (NKN) films have been investigated. Modified Sawyer-Tower circuit has been used to trace the hysteresis loop (P-E). The value of maximum polarization, Ps and coercive field, Ec was found to be 6.58 µC/cm2 and 4.10 kV/cm respectively. The polarization fatigue study has been carried out. The experimental polarization switching transients were fitted well with the Kolmogorov-Avrami-Ishibashi (KAI) nucleation theory The maximum polarization switching current (imax) and maximum switching time (tmax) have been measured as a function of the applied field. The activation field (), dimensionality (n) and switching time have been determined by employing the KAI model to the experimental switching transients. The atomic force microscopy (AFM) has been employed to estimate the grain size (~ 72 nm) and root mean square roughness (rms) (~ 130nm) of the (NH4)0.39K0.61NO3 films and has been correlated with the switching properties.