Synthesis and Dielectric Relaxation Studies of KxFeyTi8-yO16 (x = 1.4–1.8 and y = 1.4–1.6) Ceramics with Hollandite Structure

Some solid solutions with the chemical composition KxFeyTi8-yO16 (KFTO) and a hollandite-like structure were successfully synthesized by modified sol–gel method. The obtained powders characterized using X-ray diffraction (XRD) scanning electron microscopy (SEM). ceramic pellets based on KFTO compressing sintering at 1080 °C for 4 h. sinters impedance spectroscopy. XRD results show that have mono-phase tetragonal x = 1.4–1.8 y 1.4–1.6. However, it was recognized phase could be broken during to form TiO2 Fe2TiO5 crystals distributed throughout volume of ceramics. A frequency dependency dielectric properties studied It found an increase in (rutile) contributes decrease losses. At same time, ceramics reduced content potassium had increased permittivity. contribution electron-pinned defect dipoles (EPDD) internal barrier layer capacitance (IBLC) permittivity estimated Havriliak–Negami equation. is shown polydisperse characteristic relaxation. observed grain boundary dipole relaxation times 1.03 × 10−6 5.51 s 0.197 0.687 s, respectively.