Abstract
The critical properties of the spin-1 Blume-Capel model in two dimensions is studied on Voronoi-Delaunay random lattices with quenched connectivity disorder. The system is treated by applying Monte Carlo simulations using the heat-bath update algorithm together with single histograms re-weighting techniques. We calculate the critical temperature as well as the critical exponents as a function of the crystal field . It is found that this disordered system exhibits phase transitions of first- and second-order types that depend on the value of the crystal field. For values of , where the nearest-neighbor exchange interaction has been set to unity, the disordered system presents a second-order phase transition. The results suggest that the corresponding exponent ratio belongs to the same universality class as the regular two-dimensional ferromagnetic model. There exists a tricritical point close to with different critical exponents. For this model undergoes a first-order phase transition. Finally, for the system is always in the paramagnetic phase.
10 More- Received 3 December 2014
- Revised 26 June 2015
DOI:https://doi.org/10.1103/PhysRevE.92.022144
©2015 American Physical Society