Nickel-Fullerene Nanocomposites as Thermoelectric Materials

Nickel films with nanovoids filled with fullerene molecules have been fabricated. The thermoelectric properties of the nanocomposites have been measured from room temperature down to about 30 K. The main idea is that the phonon scattering can be enhanced at the C-60/matrix heterointerface. The distribution of atoms within the Ni and Ni-C-60 layers has been characterized by Auger depth profiling. The morphology of the grown samples has been checked using cross-sectional scanning electron microscopy (SEM). The Seebeck coefficient and electrical conductivity have been addressed employing an automatic home-built measuring system. It has been found that nanostructuring using Ar+ ion treatment increases the thermopower magnitude over the entire temperature range. Incorporating C-60 into the resulting voids further increased the thermopower magnitude below approximate to 200 K. A maximum increase in the Seebeck coefficient has been measured up to four times in different fabricated samples. This effect is attributed to enhanced scattering of charge carriers and phonons at the Ni/C-60 boundary.

Automated summary

In this study, nickel films with nanovoids filled with fullerene molecules were successfully fabricated, which exhibited special thermoelectric properties. It was found that phonon scattering at the C-60/matrix heterointerface can be enhanced. The distribution of atoms and morphology of the materials were characterized by Auger depth profiling and scanning electron microscopy (SEM). Measurements showed that nanostructuring using Ar+ ion treatment increased the thermopower magnitude over the entire temperature range.