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Defective perovskite SrTiO3 has been synthesized by rapid solidification of its melts obtained from arc-melting treatment. As a result of rich and stable defects implanted in SrTiO3, the bandgap was narrowed from 3.29 eV to 3.08 eV. Correspondingly, the defective SrTiO3 powders exhibit highly enhanced photocatalytic performance.

Direct coagulation casting is a novel near-net-shape method for forming ceramic green bodies from homogenous high-solids-loaded particle suspensions. It is based on the principle of the in situ coagulation of a powder suspension via a reaction-rate-controlled internal-enzyme(urease)-catalyzed reaction after casting. Low-viscosity ( 62 vol%) of SiC, boron, and carbon powder mixtures with a high surface area (>7-10 m 2 /g) have been prepared at pH 10. Salt ions (up to 1-2 mol/L) are created by the urease-catalyzed decomposition of urea, to destabilize the suspensions. The coagulation kinetics and the strength of the wet green bodies have been investigated. The reaction rate is strongly dependent on the temperature (in the range of 5°-30°C) and the enzyme concentration (for the range of 4-16 units/g SiC) and is independent of the substrate (urea) concentration for urea concentrations of

A water-based route for processing s-Si3N4 from alpha-Si3N4, Al2O3, and Y2O3 powder mixtures was established. The surface charges and isoelectric points of the three different powders were investigated within the pH range from pH 3 to pH 12. Citric acid diammonium salt was found to be an effective deflocculant for shifting the isoelectric points to pH 3.5 for Al2O3 and to pH 6 for Y2O3. Aluminum hydroxide (Al(OH)3) showed strong interaction with the Si3N4 powder, shifting the isoelectric point from pH 7 to pH 5.5. Low-viscosity, high-solids-loading suspensions (60-63 vol%) thus were possible at pH 9.7. The preparation of homogeneous and stable suspensions with a solids content of ≤61 vol% and a viscosity

The pseudoelastic behaviour of 12 mol% Ce–TZP + 10 wt% Al2O3 ceramics in the loading–unloading cycles was found for the first time at room temperature, and corresponding reversible tm martensitic transformation mechanism was clearly identified the possibility of reversible ferroelastic domain switching at room temperature was also discussed.