Abstract:
This paper considers the effect of adding niobium oxide (Nb2O5
) to ferroelectric ceramics
based on calcium titanate (CaTiO3
), and establishes a connection between the observed alterations
in strength and dielectric properties and the variation in the Nb2O5 dopant concentration in the
ceramics’ composition. The method of mechanochemical solid-phase synthesis was used as the main
method for obtaining the ceramics, followed by thermal sintering under specified conditions in order
to form a stable phase composition of the ceramics, and to initialize phase transformations in the
composition. Based on the assessment of the phase composition of the resulting ceramics, it was
determined that a growth in the Nb2O5 dopant concentration beyond 0.10 mol results in the formation
of an orthorhombic-phase CaNb2O4 of the Pbcm(57) spatial system, the weight contribution of which
grows. A growth in the Nb2O5 additive concentration results in the formation of two-phase ceramics,
the formation of which allows for an enhancement in the mechanical strength of ceramics and
resistance to external influences. During the study of the dependence of the strength properties
on the dopant concentration alteration, a three-stage change in hardness and crack resistance was
established, regarding both structural ordering and phase transformations. The measurement of
dielectric characteristics showed the direct dependence of dielectric losses and the dielectric constant
on the phase composition of ceramics.
