Raman spectroscopy of submicron KNO3 films. II. Fatigue and space-charge effects

Raman spectroscopy of KNO3 thin-film ferroelectric memories has been performed as a function of film thickness, temperature, annealing procedures, and read-write cycles (fatigue). The results show that conversion to phase II is not the cause of failure in these memory devices, in agreement with the x-ray results of Schaffer and Mikkola. Waiting time effects are in accord with the space-charge theory of Takahashi.