Abstract:
In this work, the structural, electrical, and mechanical properties and phase composition of
high-content cubic zirconium oxide ceramics stabilized with Ca were investigated. The novelty of
this work lies in evaluating the potential use of porous ceramics obtained using calcium carbonate
as a matrix for dispersed nuclear fuel. Experimental samples were prepared using solid-phase
synthesis through sintering in air at 1500 ◦C. The X-ray diffraction method and Raman spectroscopy
showed that the fraction of the cubic zirconium oxide ZrO2
-c phase gradually increased as the
mass concentration changed from Cw = 0.00 to Cw = 0.15, and the CaZrO3 phase was present at
concentrations of Cw = 0.20 and Cw = 0.25. When the phase composition was altered, significant
changes occurred in the internal microstructure of the ceramics due to the processes of grain sintering
and pore formation. Quantitative XRD analysis demonstrated the incorporation of Ca into the cubic
structure of the ZrO2
-c polymorph. Dielectric spectroscopy at low frequencies revealed that the
synthesized ceramics had a dielectric constant of 16.8–22 with a low dielectric loss of ~ 0.005. The
microhardness value at a load of 200 kgf (HV0.2) of the obtained samples varied between 5 and
12 GPa and depended on the internal microstructure and phase composition. The obtained results
clearly indicate that the mechanical and electrical properties and phase composition of synthesized
ceramics make them suitable as a matrix for dispersed nuclear fuels.
