Papers by Keyword: Remnant Polarization

Abstract: Multiferroic materials, which simultaneously exhibit ferroelectricity and ferromagnetism, have recently stimulated a sharply increasing number of research activities for their scientific interest and significant technological promise in the novel multifunctional devices. Natural multiferroic single phase compounds are rare, and their magnetoelectric response are relatively weak at room temperature. In contrast, multiferroic composites improve the magnetoelectric coupling at room temperature which can have potential applications in data storage, sensors, spintronics and filters. In view of this, Multiferroic BiFeO3 –BiCoO3 (BF-BC) composite thin films have been prepared by the spray pyrolysis method, where (110) - oriented texture was obtained. X-ray diffraction analyses confirmed that BF-BC composite films were highly (110) textured. The AFM images show that the films were uniform, dance and of nearly spherical shape nanoparticle with size of 18 nm. The (110) - texture BF-BC composite films exhibits improvement in remanent polarization and coercive field with very low leakage current. The optical properties of the composite films have been studied and correlated with their structural parameters.

Abstract: Effects of amount of Ca on crystal structure, microstructure, ferroelectric properties, and dielectric properties of the CaxSr2-xBi4Ti5O18 (CSBTi-x) ferroelectric ceramics were investigated. The results show that single-phase layered perovskite ferroelectrics were obtained and no appreciable secondary phase was found.Ca-doping results in a notable enlargement of remnant polarization 2Pr. The 2Pr of CSBT-0.15 reaches a large value, the remnant polarization 2Pr and coercive field 2Ec were 18.1µC/cm2 and 120.2kV/cm, respectively. Dielectric constant and dielectric loss of CSBT-0.15 was also measured, showing dielectric constant εr=199~194 and dielectric loss tanδ=0.02~0.014 over the range of 100 kHz~1MHz, respectively.

Abstract: In this study, the effects of oxygen gas plasma on the surface treatment of Ba(Zr0.1Ti0.9)O3 (BZT) films are investigated. The influence of plasma on the structure is developed by using X-ray diffraction patterns and the electrical characteristics are developed by using the MIM and MFIS capacitor structure. Experiment results clearly indicate that the electrical characteristics of BZT film have improved effectively within oxygen plasma surface treatment.

Abstract: In this study, ferroelectric thin films of Ba(Zr0.1Ti0.9)O3 were successfully deposited on Pt/Ti/SiO2/Si substrate under the optimal rf magnetron sputtering parameters, and their electrical and ferroelectric characteristics were investigated. The MFMIS structure of Al/Ba(Zr0.1Ti0.9)O3/ Pt/Ti/SiO2/Si was proposed in order to be applied as NDRO FRAM applications. From the experimental results obtained, the dielectric constant and the leakage current density of BZT films were about 200 and 1×10-9A/cm2, respectively, under the electrical field of 1 MV/cm. Besides, the saturation polarization and coercive field of Ba(Zr0.1Ti0.9)O3 films were found to be 4 μC/cm2 and 25 kV/cm, respectively, as the frequency of 103 Hz was applied. The variations of saturation polarization and coercive filed of films under various frequencies ranging form 102 to 106 Hz were also discussed.