Direct syntheses of La n+1Ni nO 3n+1 phases ( n=1, 2, 3 and ∞) from nanosized co-crystallites

Abstract

A new direct route for the “bottom up” syntheses of phases in the La n +1Ni n O 3 n +1 series ( n=1, 2, 3 and ∞) has been achieved via single-step heat treatments of nanosized co-crystallized precursors. The co-crystallized precursors were prepared using a continuous hydrothermal flow synthesis system that uses a superheated water flow at ca. 400 °C and 24.1 MPa to produce nanoparticulate slurries. Overall, a significant reduction in time and number of steps for the syntheses of La 3Ni 2O 7 and La 4Ni 3O 10 was achieved compared with more conventional synthesis methods, which typically require multiple homogenization and reheating steps over several days.