Slow Trap Charge Repositioning Processes and the Polarization of CaCu_3Ti_4O_(12)

摘要

Slow trap charge repositioning processes between the field perpendicular boundaries and field parallel boundaries are put forward to explain the nonlinear to linear change of the I (V) character of CaCu_3Ti_4O_(12) (CCTO). Large polarization variations, which obviously behave as a permittivity peak were found in the charge repositioning process. The anisotropic multipole polarization that occurs in the charge repositioning process is suggested to be the reason for the enormous polarization variation and also could be the origin of colossal dielectric constant of CCTO.