Hydrogen in Compounds and Alloys with A15 Structure

In the present work, a theoretical study of atomic ordering in the A3BCx alloy is carried out. The mutual influence of the ordering and solubility of impurity C in the A3B alloy is studied. The dependences of solubility on the composition of the alloy, temperature, degree of long-range order are found and studied. In addition, the criteria for the manifestation of extremity in the concentration and temperature dependences of solubility are obtained. The atomic ordering is studied using the average-energies’ method; the features of the C impurity solubility in the A3B alloy are elucidated using the configuration method. Experiments confirming the results of the theory are currently unknown to authors. However, the available experimental data on determining the temperatures of martensitic transformation (Tm) and superconducting transition (Tc) for the Nb3SnHx alloy allow us to hope and assert a possible agreement between the data of theory and experiment.