金原子在熔融玻璃表面的凝聚特性

AGGREGATION CHARACTERISTICS OF GOLD ATOMS DEPOSITED ON MOLTEN GLASS SURFACES

研究了沉积在熔融玻璃表面的金原子的扩散、凝聚以及结晶行为 .实验结果表明 :金原子在胶状的玻璃表面先形成具有特征结构的网状薄膜 ,其中金原子晶粒直径约为 2 0nm ;然后网孔逐渐增大直至薄膜破裂 ,金原子凝聚成准圆形的团族 ,其饱和直径约为 1 2 μm ,扩散系数为 10 -7— 10 -8cm2 /s数量级 ;通过快速且准无规地扩散 ,准圆形团簇最终凝聚成直径约为 5 0

The diffusion, aggregation and crystallization characteristics of gold atoms deposited on molten glass surfaces are studied. Experimental results indicate that the gold atoms first form a characteristic web-shaped Au film on the colloid glass surface,and the average diameter of the crystal grains in the film is about 20 nm. The area of the meshes gradually increases and then the whole film tatters. Thus the compact clusters are formed. The saturated diameter of the compact clusters is about 1.2 mum and its diffusion coefficient D is of the order of 10(7)-10(8) cm(2)/s. The compact clusters diffuse on the molten glass surface quickly and quasi-randomly,and finally large ramified aggregates with diameter of about 50 mum from.