Tham khảo tài liệu 'ferroelectrics material aspects part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 270 Ferroelectrics - Material Aspects closed circuit measurements for each composite and combined composites in parallel which are showed in Figure 14. Fig. 14. Composites A B C D voltage measurement with open circuit right and closed circuit left . Fig. 15. Energy harvesting analysis. means parallel connection represents a series connection. Lead Titanate-Based Nanocomposite Fabrication Characterization and Application and Energy Conversion Evaluation 271 Experimental results show that an open circuit output voltage of Vpp are generated while in closed circuit the peak to peak voltage generated is V because of the impedance of the capacitor. Figure 15 shows the energy analysis of the experiments for different configurations of the composite films. It can be seen the increasing energy supplied when the composite films are connected in parallel. The useful energy after 10 min by four composite films is about ten times higher than the energy generated by one composite film. The values of energy in Figure 15 were calculated from the measurement of the output voltage against time using the following relation 1 U 1CV2 6 where U is the available energy and V is the voltage measured on the capacitor. The voltage was measured during the charge of the capacitor due to the deformation of the composite films by the applied stress. 5. Conclusions Composite films made of PZT ceramic immersed in PVDF polymer matrix were obtained with 0-3 connectivity. The method of synthesis can provide different structure of the ceramic and also can provide ceramic particles with different size distribution which are important parameters for the electroactive properties of the sample. The inclusion of a semiconductor phase separately or coating the ceramic particles improve the poling process of the composite avoiding timing consuming and high applied electric field to polarize the ferroelectric ceramic particles immerse into the polymer matrix. The advantages of recovered particles .
