Giant Dielectric Response of Corundum Structure Fe0.7Cr1.3O3Nanocrystallite

We report the structure and dielectric properties of Fe0.7Cr1.3O3nanocrystallites synthesized by co-precipitation method. X-ray diffraction shows that the nanoparticles possess a typical corundum structure and no other impurity phases are observed. These nanoparticles exhibit a high dielectric permittivity (ε′ ∼ 103) at room temperature below 1 kHz. The dielectric relaxation follows the thermally activated process with activation energy of 0.226 eV. Both components of grain relaxation and grain boundary relaxation times were extracted from modulus spectra. The internal barrier layer capacitance (IBLC) effect is responsible for observed high dielectric response in these nanoparticles.