Iron nanoparticle formation in a metal–organic matrix: from ripening to gluttony

A simple method for the fabrication of metal nanoparticles is introduced. Heating metal–organic crystals in vacuum results in the formation of well-defined metal particles embedded in a carbon matrix. The method is demonstrated for iron phthalocyanine. At 500 °C homogeneously distributed iron nanoparticles with a reasonably narrow size distribution form by nucleation and ripening. After this initial phase the formation kinetics changes drastically. The particles move in the matrix to incorporate material. The ‘gluttony’ phase shows astonishing similarities with the search for nutrition of living micro-organisms. Particle formation, ripening and gluttony are followed in situ by transmission electron microscopy.