For modelling thermodynamic properties of the Fe-Cr alloys necessary to know the concentration dependences of the Debye temperature, the lattice parameter, the elastic moduli, the average magnetic moment, and the Curie temperature. The investigations are performed on iron alloys with chromium or vanadium in the concentration range 2–8 at %. The lattice parameters of the alloys are determined by comparing them with a standard sample placed on the surface of the sample under study. As the standard, a silicon crystal is used, and its lattice parameter is measured by the high-precision Bond method. The Debye temperatures of the alloys are determined from the temperature dependences of the integrated X-ray diffraction line intensities. The specific magnetization is measured by the Faraday method to compare the magnetic properties of Fe-Cr and Fe-V alloys. The partial magnetic moment of the iron atom is shown to increase with the alloying-element concentration.