The electrical resistivities of nanostructured aluminium films at low temperatures

Abstract

The electrical resistivities of nanostructured aluminum (nano-Al) films grown onto quartz substrates were measured from 8 K to 300 K by the four-point probe method. The nano-Al films show a temperature (T)-dependent electrical resistivity in the form of T4 and T3, different from that of the coarse-grained bulk Al. The T4 item increases with increasing the film thickness while the T3 item is just vice versa to indicate the effect of grain boundaries and surfaces on the intrinsic resistivity becomes weak with increasing the film thickness. The residual electrical resistivity in nano-Al films is further revealed to be the 2–3 orders magnitude larger than the one in the coarse-grained bulk Al and decays with increasing the film thickness. The background mechanism is deduced to result from the scattering of electrons by the grain boundaries and surfaces.