Superconducting property in tungsten containing amorphous carbon composite

Abstract

Superconductivity in tungsten-containing carbon-oxide film was reported. The film with 500 nm thickness was deposited onto polycrystalline silicon-oxides using chemical vapor deposition and co-sputtering of tungsten metal target. The structure of the film was investigated by Raman spectroscopy and X-ray diffraction measurements and the results indicated that the structure of the film is amorphous. The temperature dependence on resistivity was measured in the temperature range of 2-300 K. At the temperature of around 4.2 K resistive superconducting transition was observed. In order that the tungsten oxide and tungsten carbide with which super-conductive transition temperature is different formed the finite cluster group, it can be understand by percolation theory that the superconducting phase of the total system appears. The diamagnetism was observed below 3.8 K, which is consistent with resistive superconducting transition.