Abstract

The optical properties of an ensemble of metal nanoparticles coated with an oxide layer have been investigated within framework of the classical theory. The influence of the electron-scattering mechanisms on the polarizability of nanoparticles is analyzed. The limiting case of a thin oxide layer is considered, and analytical expressions for the real and imaginary parts of the polarizability are derived. The evolution of the frequency dependences of the polarizability and extinction coefficient upon variation in the particle size and oxide-layer thickness is investigated. It is shown that the consideration of the size dependence of the surface component of the relaxation time changes the character of the size dependence of the frequency of surface plasmons of two-layer nanoparticles.

中文翻译：

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球形金属氧化物涂层的光学性质

摘要

在经典理论的框架内已经研究了覆盖有氧化物层的金属纳米颗粒的整体的光学性质。分析了电子散射机制对纳米粒子极化率的影响。考虑到薄氧化层的极限情况，并得出了极化率实部和虚部的解析表达式。研究了极化率和消光系数随粒度和氧化物层厚度变化的频率依赖性的演变。结果表明，考虑到弛豫时间的表面成分的尺寸依赖性，改变了两层纳米颗粒的表面等离激元频率的尺寸依赖性。