Papers by Keyword: Electrical Fatigue

Abstract: In recent years ferroelectric polymer-based nonvolatile memory devices have attracted much attention due to their flexibility, transparency and ease of production. However, their electrical stability is seldom studied. In this letter we report the observation of electric fatigue in metal/ferroelectric polymer/SiO₂/p-Si capacitor memories, which is compared with the electric fatigue obtained from metal/ferroelectric polymer/p-Si capacitors. Our experiments indicate that the existence of SiO₂ layer has greatly improved the fatigue endurance in metal/ferroelectric polymer/SiO₂/p-Si capacitors. We also discuss the possible mechanism causing this improved fatigue endurance.

Abstract: Electrical fatigue tests have been conducted on PLZT ferroelectric ceramics. It was found that the higher the applied electrical field magnitude, the faster the Pr decreases; the samples under the same electrical field magnitude but with square wave have higher fatigue rate than that of sine wave. It was observed that at low frequency of applied field (50Hz and 500Hz), the polarization decreased very quickly and dropped below 70% of the original value within 106.2 switching cycles, however, when fatigue test were conducted at high frequencies of 100kHz and 300kHz, the polarization did not change significantly even after 109 cycles. The SEM analysis indicated that the facture mode was mainly of trans-granular for the virgin non-fatigued sample, while of inter-granular for the fatigue sample. The quantitative information on the 90° domain switching was measured in situ using X-ray diffraction. The effects of electrical characters on electrical fatigue behavior were explained according to the mechanism of electrical fatigue in PLZT ferroelectric ceramics.

Abstract: In this study, both mechanical and electrical fatigue properties of electrorheological (ER) materials whose global characteristics can be controlled by an external electric field are experimentally evaluated. In order to investigate the mechanical fatigue property, a linear reciprocating apparatus is devised and operated by the hydraulic unit. Two important characteristics of methylcellulose based ER material: the field-dependent yield stress and current density are investigated as a function of the operating cycle. The electrical fatigue property is investigated by applying high voltage to the ER material domain through the electrode gap. The voltage is imposed in on-off manner for the specific cycles by changing the field intensity. The yield stress and current density of the ER material are evaluated at each specified cycle and surface roughness of the electrode is observed as well.