Magnetic properties of a hexagonal nanowire system with mixed spin: Application of the stochastic Glauber dynamics with mean-field approximation

The Glauber stochastic dynamics with mean-field approximation has been applied to study the magnetic behavior of a mixed spin nanowire structure. Considering a hexagonal symmetry of the distribution of the sites, the whole lattice was interpreted as composed of two sub-lattices, a midland chain of spin-1/2 and an outer shell hexagonal of spin-1. Through the curves of the Lyapunov exponent and of the order parameters, the magnetic phase diagrams were plotted relating the magnitude of the external magnetic field with the temperature, (T, h(o))(D). For negative values of the anisotropic constant D the system showed more than one temperature of phase transition for a same magnitude of external magnetic field. This split of the phase transition branch was understood as a phase transition decoupling of the two sub-lattices. The reason for this phase transition decoupling is a competition between the states S = +/- 1 and S = 0 just in one of the sub-lattices. This behavior had not been observed in the absence of an oscillating magnetic field.