Facile synthesis of high-entropy rare earth titanate nanopowders with excellent sintering activity

High-entropy rare earth titanate (HET) nanopowders with good dispersion were successfully synthesized by a simple polyacrylamide gel method. The particle size and agglomeration degree of the HET nanopowders were greatly influenced by the mole ratio of acrylamide to titanium (AM/Ti) and calcination temperature. Moreover, the synthesis temperature was decreased with the increase of the mole ratio of AM/Ti. The as-synthesized HET nanopowders possessed high sintering activity, which could be sintered into fully dense bulks at 1500 degrees C for 2 h. The sintered HET bulks exhibited the high hardness of 13.45 GPa, large Young's modulus of 254 GPa, and relatively low thermal conductivity of 2.14-2.29 W/(m & sdot;K) in the temperature range of 25-400 degrees C. This study provides a facile synthesis method for producing HET nanopowders with excellent sinterability.