Real-space renormalization-group study of the two-dimensional Blume-Capel model with a random crystal field
N. S. Branco, B. Boechat
The phase diagram of the two-dimensional Blume-Capel model with a random crystal field is investigated within the framework of a real-space renormalization-group approximation. Our results suggest that, for any amount of randomness, the model exhibits a line of Ising-like continuous transitions, as in the pure model, but no first-order transition. At zero temperature the transition is also continuous, but not in the same universality class as the Ising model. In this limit, the attractor (in the renormalization-group sense) is the percolation fixed point of the site diluted spin-1/2 Ising model. The results we found are in qualitative agreement with general predictions made by Berker and Hui on the critical behavior of random models.
arXiv:cond-mat/9708043•Physical review. B, Condensed matter•Nov 1, 1997•84 citations