One of the fundamental directions in the use of ion implantation of metals is the creation of surface alloys of any composition. And their quantitative characteristic is the distribution of atoms of the impurity element in depth of the surface layer of the metal substrate [1][2][3][4][5]. In the study of the contribution of each component in changing the electronic structure, emission-adsorption and catalytic properties of multicomponent metal alloys, the creation of particularly pure metal solid solutions, as well as the determination of the actual concentration of alloying elements and their distribution in the surface layer of crystals are of great value. To study the distribution profiles of the concentration of ion-implanted atoms of refractory metals in alloys based on refractory metals, the method of layer-by-layer analysis using Auger electron spectroscopy in conjunction with an argon ion cannon is used. In this work, on the example of implantation of low-energy molybdenum ions into a single crystal of niobium facet (100), the features of creating surface alloys based on refractory metals with a low concentration of the alloying element and the distribution of the ion-implanted metal in the near-surface region of the crystal are studied [5][6][7][8][9].