2026-06-27T15:46:04Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/519172023-08-25T16:08:46Zcom_20.500.14352_14col_20.500.14352_15

Fernández Pérez, Luis Antonio Gordillo Guerrero, A. Martín Mayor, Víctor Ruiz Lorenzo, J. J. 2023-06-20T11:17:11Z 2023-06-20T11:17:11Z 2008 0094-243x 10.1063/1.3033359 https://hdl.handle.net/20.500.14352/51917 http://dx.doi.org/10.1063/1.3033359 http://scitation.aip.org/ We present a detailed numerical study on the effects of adding quenched impurities to a three dimensional system which in the pure case undergoes a strong first order phase transition (specifically, the ferromagnetic/paramagnetic transition of the site-diluted four states Potts model). We can state that the transition remains first-order in the presence of quenched disorder (a small amount of it) but it turns out to be second order as more impurities are added. A tricritical point, which is studied by means of Finite-Size Scaling, separates the first-order and second-order parts of the critical line. The results were made possible by a new definition of the disorder average that avoids the diverging-variance probability distributions that arise using the standard methodology. We also made use of a recently proposed microcanonical Monte Carlo method in which entropy, instead of free energy, is the basic quantity. eng open access First Order Phase Transition in a 3D disordered system journal article