用Mevva离子源，将Ag离子注入到石英玻璃中形成纳米晶粒。离子注入的能量为90keV，剂量分别为5×1015、1×1016、3×1016、5×1016、1×1017ions/cm2。X光电子能谱（XPS）分析纳米)Ag颗粒没有发生化学反应，说明Ag 仍以金属态形式存在。光学透射率测试表明，吸收峰的位置在400nm，当剂量大于5×1016ions/cm2时，发现在400nm左右有一伴峰。分析表明400nm的峰来源于表面等离子体共振吸收，而400nm的伴峰是注入离子形成了少数非常大的纳米颗粒以及纳米颗粒之间相互作用引起的。样品退火后，表面等离子体共振吸收峰红移，而伴峰消失。随着退火的温度升高，峰位红移越大，说明纳米颗粒尺寸增大。

采用MEVVA源（metal vapor vacuum arc ion source）引出的强束流脉冲Ag，Cu离子先后注入到SiO2玻璃，x射线光电子能谱仪（XPS）分析显示Ag，Cu大多仍为金属态,有部分氧化态Cu存在。透射电镜观察分析和光学吸收谱都表明在衬底中形成了纳米合金颗粒。结合有效媒质理论,得到模拟的光学吸收谱，与实验结果基本符合，较好地验证了以上结论。样品退火后颗粒发生分解，分解的颗粒在氧化气氛下被氧化，且有部分向样品表面蒸发；在还原气氛下氧化态元素被还原并成核生长。故可通过改变退火条件对纳米颗粒的成核生长进行调制。

The Ag ions were implanted in an amorphous SiO2 film, which was placed in a sample chamber of TEM. The concentration and size distribution of the Ag nanocrystals as functions of both the ion dose and the annealing temperature were examined in-situ by using this TEM. The selected diffraction pattern determined the Ag nanocrystal's presence and the dark field micrograph showed the shape and the concentration of the Ag nanocrystals. The implantation results demonstrated an average size diminution and a significant concentration increase of the Ag nanocrystals when the dose increased. The annealing results showed a loss of silver at 300℃ and above.

We report on the formation of alloy nanoclusters in silica by Ag/Cu ion sequential implantation. The formation of alloy nanocluster has been evidenced by optical absorption spectra, selected area electron diffraction and energy dispersive X-ray spectra. The microstructure characters of nanoclusters have been studied by high resolution transmission electron microscopy. The lattice distortion of some nanoclusters has been observed. A model has been given to explain the distortion. Some defects (partial dislocation, stacking faults) have been found in nanoclusters.

Ag-Cu alloy nanoclusters have been formed by sequential ion implantation. As the as-implanted sample is annealed in a reducing atmosphere, the optical absorption spectrum displays a new shoul- der peak. Transmission electron microscopy bright-field image, selected area electron diffraction pattern and high-angle annular dark field scanning transmission electron microscopy image analy- ses show that core-shell nanoclusters have been fabricated. The evolution of core-shell nanoclusters at elevated temperature was also studied.