MAGNETIC EFFECT ON THE CRITIC TEMPERATURE OR ORDER-DISORDER PHASE TRANSITION OF METALLIC BINARY ALLOYS

__Ernesto López-Chávez__^{+}, Fray de Landa Castillo-Alvaro*, Escuela Superior de Física y Matemáticas IPN, Edificio 9 UP "ALM", Zacatenco Del. G. A. Madero, México, D.F. C.P. 07738 México.

The order-disorder transition taking place in a magnetic binary alloys are studied within a microscopy theory. The internal energy of the system is calculated from the electronic structure as obtained in the solution of the Hubbard hamiltonian in the Cluster Bethe Lattice approximation. This approximation allows to include short-range order effects. The configurational entropy is calculated in the Bethe approximation and the critic temperature of metallic binary alloys A_{x} B_{1-x} as function of x is obtained.

We apply the theory to the CoFe system and the results are compares with experimental data.