The effect of co-precipitation temperature on the crystallite size and aggregation/agglomeration of GdFeO$_3$ nanoparticles

In this work, a series of GdFeO$_3$ nanopowders was successfully synthesized via a reverse co-precipitation technique at different solution temperatures (0, 25 and 50 $^\circ$C) followed by thermal treatment. Co-precipitated hydroxides and heat treatment products were analyzed using EDXS, DTA-TGA, PXRD, ASA and LD methods. It was shown that the formation temperature of GdFeO$_3$ nanoparticles varies in the range of 737.5–758.8 $^\circ$C and total weight loss varies in the range of 23.6–26.4% depending on the temperature of initial solutions. The specific surface areas of nanopowders were found to be strongly dependent on the factor mentioned above and belong to 2.5–16.3 m2/g values interval. The hierarchical structure of the obtained nanopowders was established and the effect of co-precipitation temperature on the average crystallite (21.4–34.3 nm), aggregate (46.2-301.2 nm) and agglomerate (33.5–40.9 $\mu$m) sizes was discussed in detail.