Diluted Ising Magnet on the Bethe Lattice

A solution is obtained for the Ising model on the Bethe lattice comprising a mixture of magnetic and nonmagnetic atoms in a thermodynamic equilibrium. The concentration and temperature dependences of spontaneous magnetization, the Curie temperature, and the percolation threshold are found together with the pair correlation functions of three types that characterize the arrangement of impurity atoms and the correlation of magnetic moments. It is demonstrated that the system with mobile impurities in the thermodynamic equilibrium can be brought closer to the system with frozen impurities by adjusting the parameters of interatomic interaction.