Preparation of Gd2Zr2O7 nanopowders by polyacrylamide gel method and their sintering behaviors

Abstract

Well-crystallized and good-dispersed Gd2Zr2O7 nanopowders with defect-fluorite structure are successfully prepared by the polyacrylamide gel method. The mole ratio of acrylamide/Gd and calcination temperature have the significant effects on the phase composition, particle size, and agglomeration degree of the Gd2Zr2O7 nanopowders. The sintering behaviors of the as-prepared Gd2Zr2O7 nanopowders are investigated at temperatures of 1200−1500 °C. The Gd2Zr2O7 nanopowders can be sintered into dense ceramics with a high relative density of 98 % at 1500 °C for 2 h. Moreover, the defect-fluorite phase of Gd2Zr2O7 transforms to pyrochlore phase of Gd2Zr2O7 with the increase of sintering temperature. In addition, the two-step sintering is performed to prepare the Gd2Zr2O7 nanoceramics using the as-prepared Gd2Zr2O7 nanopowders as starting materials. This work presents a simple and industrially feasible approach for preparing the Gd2Zr2O7 nanopowders with excellent sinterability.