Cole-Cole analysis and optoelectronic properties, using VEELS, of KNNS ferroelectric ceramics

In this work, Cole-Cole analysis and optoelectronic properties were carried out on K0.1Na0.9Nb0.97Sb0.03O3 (KNNS) ferroelectric ceramics with tetragonal phase. Moreover, some evidence of the 180° domains, relating the electronic interband transitions (Jcv) and the Cole-Cole plot obtained from the complex dielectric function constants. Both obtained by Kramers-Krӧnig analysis. The experimental method enabled monitoring the materials properties of the material between inter-bands transitions and plasmons. Concerning the optical reflection coefficient observed from KNNS, the observed values of reflection coefficients were about 15% for an energy loss of 0 eV and a peak value at about 32% at 5 eV, followed by a second peak equivalent to 18% at 11 eV. The number of effective electrons (neff) participating in the inter-band transitions of the KNNS material is relevant up to 40 eV. These results suggest that KNNS could be a material to enable terahertz waveguide, enabling a new generation of high-speed communications devices. [Display omitted] •Cole-Cole analysis and optoelectronic properties were carried out on KNNS (K0.1Na0.9Nb0.97Sb0.03O3)•Ferroelectrics 180° domains is identified by HRTEM.•Electronic Interband transitions Jcv and the Cole-Cole plot obtained from the dielectric function.•The number of effective electrons (neff) in the inter-band transitions of the material is up to 40 eV.•These results suggest that KNNS could be a material for terahertz waveguiding.