Crystallisation of Ge nanoclusters in SiO2 caused by electron irradiation in TEM

Ge nanoparticles fabricated by ion implantation technique in SiO2 thin film crystallise after irradiation with a high-energy electron beam. The crystallisation process depends on the irradiation fluence and flux. Irradiation with a fluence above 6x103 C/cm2 results in cluster growth and above 4x104 C/cm2 in crystallisation. An irradiation with flux below 150 A/cm2 leads to the crystallisation of Ge nanoparticles in the form of single crystals. For irradiation flux above this value the formation of twinned and multiply twinned particles (MTP) was observed