Use of effective medium theory to model the effect of the microstructure on dc conductivity of nano-titanium films

摘要

The direct current (dc) conductivity of nano-titanium films deposited by dc magnetron sputtering depends on the film thickness. This dependence is transformed into the dependence of effective conductivity on volume fraction and compared to a simulation based on effective medium theory (EMT). The Maxwell-Garnett (M-G), Bruggeman, Sheng, Landau-Lifshitz/ Looyenga (LLL), and Monecke models in EMT are employed. In addition, modifications to the M-G model for variable particle shapes are examined, which give quite good agreement with experiments. Both theoretical prediction and experimental results confirm the essential underlying role of microstructure in the electrical property of nano-titanium films.