Fig. 4. (a and b) TEM images and shape distributions and (c and d) size distributions of magnetite nanoparticles obtained by (a and c) 2 vol% NH3 and (b and d) 0.5 vol% NH3 diffusion in 30 mL of 3 mM Fe solution, which show a trend from smaller, rounded particles to larger, facetted crystals. Insets in (c and d): shape distributions of the 25–35 nm size fractions in each sample, which show a similar trend. Reproduced from ref. 83.
