有效介质理论在Ag-MgF_2复合纳米颗粒薄膜中的应用

Application of Effective Medium Theories to Ag-MgF_2 Granular Film

将描述弥散体系行为的Maxwell Garnett理论与Bruggeman理论应用于Ag MgF2 复合纳米颗粒薄膜 ,分别计算出该复合体系在 2 5 0nm～ 830nm波段范围内的光学常数n、k随波长λ的变化 ,并与实验结果进行比较。发现较之普遍采用的Maxwell Garnett理论 ,由Bruggeman理论计算出的n λ、k λ曲线的峰位、峰宽及峰位随Ag组分质量百分率的位移都与实验结果更为接近。

The optical constant, n and k ,of the Ag MgF 2 nanoparticle cermet films and their variations with wavelengths,ranging from 250 nm to 830 nm,were studied on the basis of Maxwell Garnett and Bruggerman theories.The results show that some physical quantities calculated with Bruggeman theory,including the peak positions of n λ and k λ curves,peak width and variations in peak position with stoichimetric shifts of Ag,agree better with the experimental observations than those evaluated with widely used Maxwell Garnett theory.The possible reasons for the disagreement between theories and experiments were tentatively explained.