Design of biocompatible high piezoelectric BaTiO_3 with Additives

摘要

Recently, the developments of lead-free materials such as BaTiO_3 have been widely investigated. However, the piezoelectricities for those materials are not superior to existing lead-included materials such as PZT. In order to design high piezoelectric materials, we propose the analytical technique, which is able to consider the influence of additives added into biocompatible lead-free piezoelectric materials BaTiO_3. Because, the additives are effective technique to improve the piezoelectricities of piezoelectric materials in general. In this research, we proposed the analytical method by using the Rietveld method to quantitatively confirm the changing of diffraction intensities for BaTiO_3 (which shows relative relationship with piezoelectricity experimentally) with changing the additive atoms at the appropriate chemical composition. Especially, the factors in the equation in regard to XRD (X-ray diffraction) diffraction intensities in the Rietveld method in order to change and improve piezoelectricities by various additives were investigated by comparing to the XRD intensity for non-added BaTiO_3. Firstly, the theoretical diffraction pattern in regard to BaTiO_3 Perovskite crystal structure were characterized by using the non-linear least square method. Secondly, the diffraction intensities for BaTiO_3 material added various additives to displace B-site of Perovskite structure for BaTiO_3 at the rate of 10% were calculated. Finally, the difference diffraction intensities between BaTiO_3(111) and BaTiO_3(111) added additives such as a periodic atoms were also calculated. As a result, the correlation factor between the atomic scattering factor and the changing amount of the diffraction intensity of BaTiO_3(111) shows strong negative correlation of-0.997 to improve piezoelectricity. And also it is confirm that the X-ray absorption rate contributes to the change in the diffraction intensity periodically in local region.