Siberian Federal University

Three novel low-temperature techniques have been developed for the synthesis of ultrafine powders (UFP) of the ferroelectric phase (Bi1-xBax)Fe1-xTixO3 doped with manganese ions. These methods are designed to significantly reduce the dielectric loss (tan δ) in the resulting ceramic piezoelectric materials. The reduction in the tan δ values is accomplished by introducing manganese in three distinct chemical forms during synthesis: a) aqueous Mn(NO3)2 solution, b) Mn(III) hydroxide gel, or c) Mn(IV) hydroxide gel. A key advantage over conventional doping is the achievement of a highly uniform distribution of the dopant, even at low concentrations (0.5–1.0 mol%), within every particle of the base UFP. Furthermore, these innovative techniques eliminate the need for a milling step, thereby preventing the common contamination of the base ferroelectric powders with silicon and aluminum impurities. Such contamination is a known factor that exacerbates the thermal degradation of piezoelectric ceramics