In this paper, the localized surface plasmon resonance (LSPR) peak of Ag-Fe and Au-Fe alloy nanoparticles for the triangular prism is calculated by using the discrete dipole approximation (DDA) method. We investigate the variation of the resonance wavelength, refractive index sensitivity, and figure of merit with the particles size and alloy compositions. We perform a comparative study on the refractive index sensitivity and figure of merit of alloys in order to find the considered (Ag-Fe and Au-Fe) alloys with high sensitivity. The refractive index sensitivity of the Au-Fe alloy is found higher than that of the Ag-Fe alloy. Therefore, to optimize the size of alloy nanoparticles (NPs) for the triangular prism, the figure of merit is calculated and observed that the optimized size is 50nm and 20 nm for Ag-Fe and Au-Fe alloys, respectively. A comparison of Ag-Fe shows that the Au-Fe alloy NPs have greater figure of merit (FOM) and thus may be more suitable for applications in biosensing.

中文翻译：

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三角棱镜中Ag-Fe和Au-Fe双金属合金的尺寸依赖性RIS和FOM：DDA研究

本文采用离散偶极近似（DDA）法计算了三棱镜的Ag-Fe和Au-Fe合金纳米粒子的局部表面等离子体共振（LSPR）峰。我们研究了共振波长，折射率灵敏度和品质因数随颗粒尺寸和合金成分的变化。我们对合金的折射率灵敏度和品质因数进行比较研究，以找到考虑的具有高灵敏度的（Ag-Fe和Au-Fe）合金。发现Au-Fe合金的折射率灵敏度高于Ag-Fe合金的折射率灵敏度。因此，为了优化用于三角棱镜的合金纳米颗粒（NPs）的尺寸，计算了品质因数并观察到，Ag-Fe和Au-Fe合金的优化尺寸分别为50nm和20nm。