N.O. Moreno

Study of the Fe-Al alloys in the Ising model for S = 2 spin by employing the effective field theory

In this work, we study the phase diagram of Fe1−qAlq alloys via site diluted spin-2 ferromagnetic Ising model by employing effective field theory. In contrast with previous studies, here, we incorporate in such model the high-spin S = 2 Fe2+ ion. We consider the same kind of the exchange interaction that of the iron-nickel alloys and we obtain an excellent theoretical description of the experimental data of the T–q phase diagram over the entire range of Al concentration q. In particular, the present calculation provides an excellent agreement with the experimental results for both the anomalous region of Al concentration q (i.e., q<0.2) and for the value of q at which the critical temperature Tc(q) vanishes (i.e., q=qc).

Monte Carlos studies of critical and dynamic phenomena in mixed bond Ising model

The phase transition of a random mixed-bond Ising ferromagnet on a cubic lattice model is studied both numerically and analytically. In this work, we use the Metropolis and Wolff algorithm with histogram technique and finite size scaling theory to simulate the dynamics of the system. We obtained the thermodynamic quantities such as magnetization, susceptibility, and specific heat. Our results were compared with those obtained using a new technique in effective field theory that employs similar probability distribution within the framework of two-site clusters.

Magnetic Properties of the Metamagnet Ising Model in a three-dimensional Lattice in a Random and Uniform Field

The Monte Carlo technique is here used for study the behavior of metamagnet Ising model in presence of random field. The phase diagram is obtained by employing Glaubers algorithm in a cubic lattice of linear size L with values ranging from 16 to 42 and with periodic boundary conditions.