Superconducting Properties of $VN-SiO_{2}$ Sol-Gel Derived Thin Films

In this work studies of structure and superconducting properties of $VN-SiO_{2}$ films are reported. The films were obtained through thermal nitridation (ammonolysis) of sol-gel derived $V_{2}O_{3}-SiO_{2}$ coatings (in a proper $V_{2}O_{3}//SiO_{2}$ ratio) at 1200°C. This process leads to the formation of disordered structure with VN metallic grains dispersed in the insulating $SiO_{2}$ matrix. The structural transformations occurring in the films as a result of ammonolysis were studied using X-ray photoelectron spectroscopy (XPS). The critical superconducting parameters are obtained. The magnetoresistance at high magnetic fields has been investigated.