實驗中以古典凝核理論為知識背景,使用的是金作為氣相凝結合成奈米粒子的源。固定鎢舟的加熱功率、收集盤高度和氬氣在腔體中的氣流。並且從中試圖得到在真空腔體中成長的壓力與粒徑大小的關係。透過各種XRD、SEM、DLS以及AFM來鑑定成長出來的粒子並且比較各種鑑定法所得到的結果,以及對照理論比較實驗與理論是否相符合,並加以討論。 實驗方法是將金放在鎢的金屬片(鎢舟)上並且置於低壓力之下讓它加熱產生蒸氣。粒子再較低溫的區域形成,並且藉由自由對流,傳輸到冷收集盤上。本實驗中所得到最主要的結論,形成奈米粒子的過程中,環境的氣壓,在一定的範圍內壓力的上升會引起平均粒子粒徑的下降。
In our experiment we use the classical nucleation theory as knowledge background. Au nanoparticles are manufactured by gas condensation method. Fixing the heating rate of tungsten boat, the position of collector and the flowing rate of argon in chamber, we find out the relation between the diameter of particles and the argon pressure in the chamber. Our samples are characterized by XRD (X-Ray diffraction), SEM (Scanning electron microscope), DLS (Dynamic light scattering) and AFM (Atomic force microscope). The results are discussed and compared with the theory. Our experiment method is to put Au shot on the tungsten boat and heat it under low pressure environment. Particles formed in the colder region of the unit are transported by free convection to a cold surface (collector). The main conclusion of our experiment is that, in a range of 10torr~20torr, the higher argon pressure causes the nanoparticles smaller.