搖鈴形奈米材料是金屬核-殼顆粒，其核和殼之間由導電的金銀合金相連。由於它們在空腔內具有非常高的電場增強，因此這些奈米粒子被認為是一類有前途的奈米粒子。以往的困境為實驗再現性和當中心金屬芯移動時造成軸對稱性的損失，進而導致奈米空腔尺寸和電場增強位置無法定義。我們的合成方法使中心金奈米棒牢固地固定在長方體框架中，形成軸對稱的奈米結構。我們經由穿透式電子顯微鏡(TEM)、掃描式電子顯微鏡(SEM)、場發射掃描穿透式球差修正電子顯微鏡的元素分析(STEM & EDS)和多功能原子力顯微鏡(AFM)定義搖鈴形奈米材料的結構。本文研究了具有不完全的金屬置換反應的穩定中間產物的消光光譜演化。透過添加不同量的Au3+離子，製備一系列從金/銀-核/殼奈米長方體到金奈米棒-金銀合金框架的搖鈴形奈米結構。可以觀察到樣品的懸浮液有明顯的顏色變化。縱向表面電漿共振波長涵蓋的位置從660到1000 nm。我們透過電磁模擬研究了光譜的變化，發現尺寸增大和空腔的形成對於光譜變化有著重要作用。

Nanorattles are metallic core–shell particles with core and shell separated by a dielectric spacer. These nanorattles are considered to be a promising class of nanoparticles because of their high electric-field enhancement inside the cavity. Limiting factors are reproducibility and loss of axis symmetry when the center metal core moves, which leads to the inability to define the nanocavity dimensions and the electric field enhancement position. Our synthetic method allows the central gold nanorod to be firmly fixed in the cuboid frame to form an axisymmetric nanostructure. We define the structure of nanorattles by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), scanning TEM & energy-dispersive X-ray spectroscopy (STEM & EDS) and atomic force microscopy (AFM). In this work, we investigate the spectral evolution of the stable intermediate products with incomplete Galvanic replacement reactions. By adding the various amount of Au3+ ion, a series of nanostructures from Au@Ag nanocuboids to Au-Ag nanorattles are prepared. The suspensions of the products show a clear color change. The longitudinal plasmon mode of the nanostructures cover from 660 to 1000 nm is prepared. We investigate the spectral shift with electromagnetic simulations and find that both size enlargement and cavity formations play an important role in the spectral shift.

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