Preparation and dielectric properties of ceramics based on mixed potassium titanates with the hollandite structure

We have studied the crystallization of potassium polytitanates (PPTs) modified in aqueous solutions of salts of various transition metals. The results demonstrate that the modified materials crystallize in the form of solid solutions with the hollandite structure. Ceramic materials obtained using the PPT/Fe, PPT/Ni, and PPT/Co systems have high dielectric permittivity in the low-frequency region (ε ~ 10⁵), whereas PPT/Cu ceramics have lower ε (~10³), retaining it to a frequency of 1 MHz, and very low dielectric losses (tanδ ~ 10^–2).