STABILIZATION OF THE DIELECTRIC PROPERTIES OF SOLID SOLUTION CERAMICS BASED ON CALCIUM-BARIUM NIOBATE

In this work, we studied the effect of a modifying additive of finely dispersed polystyrene (2 wt.%) on the dielectric and pyroelectric properties of the ceramic samples Ca 0.3 Ba 0.7 Nb 2 O 6 ( CBN 30) and solid solutions based on it with the addition (5%) of SrTiO 3 or LiTaO 3, obtained by the solid-phase synthesis method. It is shown that the presence of polystyrene during the sintering of solid solution ceramics based on CBN30 leads to the formation of nanosized pores in the samples and, as a result, leads to a significant decrease in the dielectric losses and a change in the nature of the permittivity dispersion in a wide frequency range of fabricated samples. As a result, the shape of the dispersion diagrams of the ceramics based on CBN 30 became similar to the dielectric dispersion of industrial samples of the piezoelectric ceramics of lead zirconate-titanate. The studies of the pyroelectric effect on polarized ceramic samples based on CBN 30 revealed that the samples sintered with the presence of polystyrene, in contrast to the samples sintered without polystyrene, have a uniform polarization distribution over the thickness.

piezoelectric ceramics, barium-calcium niobate, Lead-free materials, modifiers, grain structure, permittivity