Transport Properties of Nitrided $VN-SiO_{2}$ Sol-Gel Derived Films

This work presents transport properties of $xVN-(100-x)SiO_{2}$ (where x = 90, 80, 70, 60 mol%) films. The films were prepared by thermal nitridation of sol-gel derived $V_{2}O_{3}-SiO_{2}$ (in proper molar ratio) coatings. The coatings obtained by sol-gel method are especially suitable for the ammonolysis because of their porosity. The microporous structure allows both a significant incorporation of nitrogen and its distribution through the film. The nitridation process of $V_{2}O_{3}-SiO_{2}$ coatings leads to the formation of disordered structures, with VN metallic grains dispersed in the matrix of insulating $SiO_{2}$. The critical temperatures of the superconducting transition of the samples $T_\text{conset}$ are about 7.5 K.