實驗採用的樣品為利用蒸鍍法所製作出5組粒徑不同的奈米金粉粒，由X光繞射譜圖實驗及原子力顯微影像，得知當粒徑小於2.9nm時，X光繞射譜圖會在散射角為230、330、540出現繞射峰，相異於的一般fcc塊材金的繞射譜圖。將3種不同的奈米金粉粒的結構利用有限尺度散射強度進行模擬，得知當奈米粉粒的粒徑越小，其繞射譜圖與塊材越不相同，由模擬結果得知，當粒徑小於2.7nm，結構發生扭曲，但無法確定原子結構是否有改變。 樣品進行穿透式吸收光譜實驗，在紫外光及可見光的波長範圍，奈米金粉粒有極強的吸收現象；在紅外光範圍則呈現較弱的吸收，且當奈米金粉粒的粒徑為1.1 nm時，其吸收率明顯強於其他較大粒徑的樣品，且在紅外光範圍(約800 nm)的吸收率會有突然減小的現象。 We made five sample of Au nanoparticle with different diameter by thermal vaporation way .We used XRD and AFM to decide the diameter of sample . When the diameter of sample is smaller than 2.9 nm，there are diffraction peaks at scattering angle 230、330、540 in X-ray pattern .These peaks are different with usual diffraction peaks of fcc structure Au. Using finite size of diffraction Intensity to simulate X-ray pattern with 3 different structure , We find that these simulation pattern according to reduction of size is different with the pattern of Au Bulk .We know that the structure of Au nanoparticle is distorted when the diameter is smaller than 2.9 nm. But We don’t sure that Au nanoparticle’s structure is changed. According to the experiment of absorption, Au nanoparticle has strong absorption at UV-VIS. Au nanoparticle has weaker absorption at IR .The absorption of 1.1 nm Au nanoparticle is stronger than other sample .
