Metal-containing diamond-like nanocomposite thin film for advanced temperature sensors

The conductivity of metal-carbon-silicon nanocomposite films considered as potential candidates for the application as wide-range temperature sensors for severe environmental conditions is studied. The films combine unique properties of amorphous carbons with a new functionality imparted by the presence of metal nanoclusters in host matrix. The deposition of carbon-silicon phase was performed using PECVD of siloxane vapors. Metals (W, Nb, and Cr) with concentration in the range from 12 to 40 at. % were incorporated in the carbon-silicon host matrix by DC magnetron co-sputtering. The conductivity of the films decreases with temperature in the range 80-400 K, being well described by the power-law dependence. The conductivity mechanism found satisfactory explanation in the framework of the model of inelastic tunneling of electrons between metal nanoclusters dispersed in carbon-silicon matrix. The parallel study of the influence of metal concentration increase on carbon phase microstructure was carried out using Raman spectroscopy.