Nanoscale multilayer structure TiO2/BaTiO3/TiO2 has been fabricated on Pt/Ti/SiO2/Si substrate by chemical solution deposition method. Highly uniform bipolar resistive switching (BRS) characteristics have been observed in Pt/TiO2/BaTiO3/TiO2/Pt cells. Analysis of the current-voltage relationship demonstrates that the space-charge-limited current conduction controlled by the localized oxygen vacancies should be important to the resistive switching behavior. X-ray photoelectron spectroscopy results indicated that oxygen vacancies in TiO2 play a crucial role in the resistive switching phenomenon and the introduced TiO2/BaTiO3 interfaces result in the high uniformity of bipolar resistive switching characteristics.

Pb(Zr0.53Ti0.47)O3 (PZT) thin film was fabricated on Pt/Ti/SiO2/Si substrate by chemical solution deposition method. Our results show a very great switchable ferroelectric diode effect (SFDE) in Pt-PZT-Au structure, which is more obvious and controllable than that in other ferroelectric thin films. The electrical conduction exhibits high rectifying behavior after pre-poling and the polarity of ferroelectric diode can be switched by changing the orientation of polarization in ferroelectric thin film. Our results also indicate that the SFDE in PZT film is highly dependent on remanent polarization and temperature. With the increase of remanent polarization, the forward current of bistable rectifying behavior observably reduces. Therefore, our measurement indicated that the biggest rectification ratio can reach about 220, which is found in 250K after +10V poling. By analyzing the conduction data, it is found that the dominant conduction mechanism of the SFDE in this sample is due to the space-charge-limited bulk conduction (SCLC), and Schottky emission (SE) may play subordinate role in forward bias voltage. Our observation demonstrates that SFDE may be general characteristic in ferroelectrics as long as proper electrodes chosen.

In this paper, we investigate the multiple stick-slip chaotic motion of an archetypal self-excited smooth and discontinuous (SD) oscillator driven by moving belt friction, which is constructed with the SD oscillator and the classical moving belt. The friction force between the mass and the belt is modeled as a Coulomb friction for this system. The energy introduction or dissipation during the slip and stick modes in the system is analyzed. The analytical expressions of homoclinic orbits of the unperturbed SD oscillator are derived by using a special coordinate transformation without any pronominal truncation to retain the natural characteristics, which allows us to utilize the Melnikov’s method to obtain the chaotic thresholds of the self-excited SD oscillator in the presence of the damping and external excitation. Numerical simulations are carried out to demonstrate the multiple stick-slip dynamics of the system, which show the efficiency of the prediction for stick-slip chaos of the perturbed self-excited system. The results presented herein this paper demonstrate the complicated dynamics of stick-slip periodic solutions, multiple stick-slip chaotic solutions and also coexistence of multiple solutions for the perturbed self-excited SD oscillator.