We have created lithium metal colloids by electron-irradiating single crystals of lithium oxide near 0°C. The striking feature is the observation of two kinds of colloids manifesting themselves as two EPR metallic lines, the narrow line corresponding to small metallic clusters (size < 1 µm) and the broad one associated with large metallic colloids visible by optical microscopy (~ 20 µm). The latter are also observed by NMR. A further indication for the presence of colloids of different types is the differing recovery behavior of the two EPR lines in an annealing treatment
