Sub-micrometre sized hematite particles with a controlled structure were prepared by forced hydrolysis of a Fe(NO3)3·9H2O aqueous solution in the presence of poly(alkylene oxide) triblock copolymer (Pluronic P123). The resulting particles show an echinoid-like shape and a narrow size distribution. After removal of the polymer by calcination at 500 C for 3 h, the resulting particles show a retai...