Discovery of strange kinetics in bulk material: Correlated dipoles in CaCu3Ti4O12A. M. Awasthi, Jitender Kumar
- Journal of Applied Physics, September 2012, American Institute of Physics
- DOI: 10.1063/1.4749398
Strange Kinetics in Colossal Dielectric Constant (CDC) Material CaCu3Ti4O12 (CCTO)
What is it about?
Huge permittivity with broad temperature- & frequency-plateaus and sub-Arrhenic (nonlinear) kinetics, both rooted in self-similar electrical non-uniformity, mark CCTO as a complex material. Crossover-evolution of independent dipoles (at high temperatures) into correlated clusters (below 100K) here rules out a thermodynamic or kinetic phase transition. Our study points to a fractal sub-configuration of Ca- and Cu-rich regions; insight being useful for tuning the CDC and the crossover temperature.
Why is it important?
Size-downscaling of material-granularity to intrinsic fractal-heterogeneity, coupled with the Maxwell-Wagner mechanism, is identified as the reason for the giant dielectric constant in CCTO. Materials engineering to enhance and control this circumstance in candidate systems points the way towards desired-bandwidth functionality across ambient conditions.