A new method to prepare plate-shaped Fe2O3 nanoparticles was investigated and their magnetic properties were characterised. First. Fe2O3 nanoparticles of similar to 6 nm in diameter were synthesised by mechanochemical processing, involving the solid-state exchange reaction Fe-2(SO4)(3) + 3Na(2)CO(3) -> Fe-2(CO3)(3) + 3Na(2)SO(4) -> Fe2O3 + 3 Na2SO4 + 3CO(2) (g) effected by high-energy ball milling and subsequent heat treatment at 400 degrees C. Next, nano-platelets were grown from the nanoparticles by further heat treatment in a salt matrix at 700 degrees C. Removal of the salt and by-product phases after heat treatment led to well-dispersed platy haematite particles of 20-200 nm in diameter with aspect ratio of 4-10. The hematite nano-platelets were weakly ferromagnetic with coercivity of similar to 160 Oe and remanent magnetisation of 0.2 emu/g. (C) 2011 Elsevier B.V. All rights reserved.