Structure and ferroelectric properties of lead-free NBT-KBT-BF ceramics

ABSTRACT

Phase formation, crystal structure parameters, dielectric and ferroelectric properties of ceramic solid solutions in the (1-y)[(1-x)(Na_0.5Bi_0.5)TiO₃-x(K_0.5Bi_0.5)TiO₃]-yBiFeO₃ system with x = 0.25, y = 0 – 0.6 has been studied. Pure samples with the pseudocubic perovskite structure were obtained by the solid state reaction method. Addition of BiFeO₃ stimulated a monotonous increase in the unit cell volume and in the Curie temperature T_m value. With increasing the BiFeO₃ content, nonmonotonous behaviour of the dielectric permittivity, a decrease in the T_ph value, a decrease in total electroconductivity and dielectric loss at the room temperature were revealed.

KEYWORDS:

• (Na_0.5Bi_0.5)TiO₃
• (K_0.5Bi_0.5)TiO₃
• BiFeO₃
• perovskite structure
• phase transitions
• ferroelectric properties
• dielectric relaxation

Funding

The work was supported by the Russian Foundation for Basic Research (Grant 15-03-03269).