The evolution of thin MgO(100) foils during in-situ ion implantation and thermal heating was followed with transmission electron microscopy (TEM) in the IVEM-TANDEM facility of Argonne National Laboratory (USA). A pre-thinned MgO foil was implanted with 100 keV Au ions at an elevated temperature of 700 K to a fluence of 1.8x10~(16) Au cm~(-2) leading to the spontaneous formation of small (2-3 nm) Au nanoclusters. Post-implantation thermal annealing at 1100 K led to coarsening of the precipitates reaching sizes of ～9 nm. Subsequent irradiation with 600 keV Au ions (passing completely through the foil) led to refining of the precipitates, a reversed ripening process. After irradiation with1x10~(16) Au ions cm~(-2), the cluster size decreases to less than ～3 nm. In another experiment, during 300 keV Kr ion irradiation, where the ions pass through the foil, a dense network of cubically shaped nanovoids was observed after a dose of 4xl0~(16) Kr ions cm~(-2).
展开▼
