Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.

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The large ferroelectric diode current modulated by bipolar polarization in epitaxial (111) BiFeO3 thin film has been observed. With the survey of different current leakage models, it is found that the space-charge limited current dominates the conduction. For the intrinsic physical understanding, the rectification of diode currents near domain coercive fields is attributed to gradient distribution of the trap charges between top and bottom electrode/ferroelectric interfaces, and the distributed charges can be reversed upon polarization reversal. Moreover, the retention time of the On and Off diode currents is over 104 s with their ratio of around 5:1.

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Electrical characteristics of monofilaments in dielectric barrier discharge plasma jets were investigated at atmospheric pressure. It is found that the shapes of monofilaments, the discharge current, the number of discharges, the breakdown voltage and the input power are dependent not only on the Ar flow rate but also on the applied voltage and exhibit complicated behaviors. Especially, the discharge current is irregular and has the oscillating pulses with positive and negative polarities. The influence of wall charges on the above parameters was discussed.

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