Evidence for Filaments inV3Si

Thin films of ${\mathrm{V}}_3$Si were deposited on various substrates such as quartz, sapphire, graphite, but principally on MgO using the hydrogen reduction of the mixed chlorides. The evaporator used for the vapor phase control of the reduction process was designed to take advantage of the principle of steady state and therefore was able to yield films with very accurate chemical compositions. Thin films ranging in thickness from 100 000 Å down to 1000 Å were deposited on MgO at a temperature of approximately 1000°C. The transition temperatures of these films were as high as 16.7°K for the thick films, but as low as 14.85°K for the thin ones. The composition of the films was checked by x-ray diffraction and x-ray fluorescence analysis. The gross composition of the films was found to depend on the composition of the vapor and the substrate temperature.