A Theoretical Model on Size Effect of Dielectric Response in DC Bias Field in Barium Titanate Ceramic System

Theoretical models of size effects in dielectric response according to DC bias field in submicrometer barium titanate ceramic system are discussed. The dielectric response contains two typical parts: intrinsic ferroelectric and the vibration of domain walls, and the total dielectric response is the summation of both. In this work, the size effects of the two parts are analyzed separately. With the combination of the two parts, a theoretical model on size effect in dielectric response in DC bias field is derived. Our research shows that finer grains help to decrease permittivity loss when a DC bias field is applied. Additionally, some commercial devices were measured to verify our model.