Synthesis of Multidoped Zirconia by Hydrothermal Method with Sequential Annealing

Over more than half a century of using zirconia in technology and industry, researchers have faced several challenges related to the performance of this material. It is believed that some issues regarding the low performance of the zirconia ceramics can be solved by using a multidoping strategy. In this study, nanoparticles with the composition (1 − x)⸱ZrO2 − x⸱MD (where MD—multi-dopant Y:Ce:Mg:Ca with cation relationship 1:1:1:1 and x = 0.05–0.25 mol. %) were synthesized using a hydrothermal method followed by annealing. XRD and Raman spectroscopy analyses demonstrated that in the concentration range of x = 0.10–0.25 mol.%, the only detectable phase in the synthesized samples was the tetragonal phase of zirconia. SEM analysis revealed that the size of the final particles ranged from 20 to 50 nm. It was demonstrated that using obtained nanoparticles as precursors for sintering leads to the formation of multiphase ceramics. The microhardness and biaxial flexural strength of the ceramic samples vary depending on the dopant concentration in the range of 600–1400 HV and 25–200 MPa respectively. Mechanical properties mostly depend on porosity and grain size in the sintered material. The study shows that the multidoping strategy has high potential to obtain new constructional ceramics and components for solid oxide fuel cells.