| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Mesoscale Phenomena in Functional Polycrystals and Their Nanostructures
|
| Presentation Title |
Modeling the Relaxor Dielectric Dispersion of Ba(1−x)Sr(x)TiO3 with a Local Phase Field Method |
| Author(s) |
Ashok Gurung, John M. Mangeri, S. Pamir Alpay, Serge M. Nakhmanson |
| On-Site Speaker (Planned) |
Ashok Gurung |
| Abstract Scope |
The solid solution Ba(1−x)Sr(x)TiO3 (BST) displays a highly tunable dielectric response, while exhibiting low losses in a broad frequency regime, including microwave. There is a need for better understanding of the influence of BST microstructure on its properties and performance. Since local polarization in BST is strongly dependent on composition, so is its response to an applied AC field. Here, we have adopted a phase field method to study the frequency dependent dielectric response of BST, while accounting for the local composition fluctuations. We connected relaxor-like features in the dielectric dispersion to local spatial inhomogeneities, such as average size of Ba-rich regions, across a wide range of temperatures. These results show that the simple coarse-grained approach to the relaxor problem is sensitive enough to reveal correlations between the frequency dependence of the dielectric response and modulations in the material morphology and microstructure. |