Polycrystalline thermosensitive ceramic oxides in CaCeNbWO8: Density, texture, and thermal aging stability

During the vacuum hot pressing sintering process, a certain thickness of graphite foil is usually used as the isolation layer to avoid the adhesion between ceramic and graphite die. Here, the graphite foil was replaced by a platinum sheet in the sintering process. The microstructure, weak texture, and electrical properties of pressure-sintered CaCeNbWO8 thermosensitive ceramics were investigated and compared with pressureless-sintered ceramics. The relative densities of the pressureless-sintered and pressure-sintered ceramics were 79.4% and 97.0%, respectively. The tetragonal scheelite structure having space group I4(1)/a (88) was further confirmed by Rietveld refinement. The corresponding (112) Pole Figures showed that the weak texture intensity changed from 2.32 to 3.08 mud. Results demonstrate that the improvement of the vacuum hot pressing sintering process is in favor of obtaining high stability thermosensitive ceramics, which might potentially be applied to the mass preparation of functional ceramics or high-density ceramics.

Automated summary

Improvements were made in the vacuum hot pressing process by replacing graphite foil with a platinum sheet, resulting in higher density and enhanced weak texture structure in pressure-sintered CaCeNbWO8 thermosensitive ceramics.