混合物薄膜折射率与膜孔洞率关系研究

The Study of the Relations Between RefractiVe Index and Porosity in Mixed Films by Coevaporation

本文对TiO_2和Ta_2O_5混合膜进行了单源共蒸发实验研究。在实验结果的基础上,提出了一个拟合TiO_2、Ta_2O_5混合膜系孔洞率的经验公式,并对混合膜的折射率的计算过程进行了改进。结果表明:理论计算与实验数据符合较好;混合物薄膜可能形成孔洞率较小的膜层,从而导致混合物薄膜折射率随混合百分比的变化曲线出现峰值。

In order to further understand the relations between refractive indexand porosity in mixed films,we did the experiments of mixed film systemTiO_2:Ta_2O_5,using coevaporation.On the basis of our experimental results,weput forward an empirical porosity expression to fit the data of TiO_2:Ta_2O_5system,and we also improved the calculating procedure of the refractive indexof mixed films.The results of theoretical calculations using our empiricalporosity expression agree with those of experiments.The results of experimentsand theoretical analysis show that it is possible that the mixed films have lessporosity than pure thin films,and those films cause a peak in the curve ofrefractive index of mixed films versus the ratio of the mixed weight.