Year: 2007
Type: article
Abstract: The present paper considers some classical ferromagnetic lattice-gas models, consisting of particles that carry $n$-component spins $(n=2,3)$ and associated with a $D$-dimensional lattice $(D=2,3)$; each site can host one particle at most, thus implicitly allowing for hard-core repulsion; the pair interaction, restricted to nearest neighbors, is ferromagnetic, and site occupation is also controlled by the chemical potential $\ensuremath{\mu}$. The models had previously been investigated by mean field and two-site cluster treatments (when $D=3$), as well as grand-canonical Monte Carlo simulation in the case $\ensuremath{\mu}=0$, for both $D=2$ and $D=3$; the obtained results showed the same kind of critical behavior as the one known for their saturated lattice counterparts, corresponding to one particle per site. Here we addressed by grand-canonical Monte Carlo simulation the case where the chemical potential is negative and sufficiently large in magnitude; the value $\ensuremath{\mu}=\ensuremath{-}D∕2$ was chosen for each of the four previously investigated counterparts, together with $\ensuremath{\mu}=\ensuremath{-}3D∕4$ in an additional instance. We mostly found evidence of first-order transitions, both for $D=2$ and $D=3$, and quantitatively characterized their behavior. Comparisons are also made with recent experimental results.
Source: Physical Review B
Authors: H. Chamati, S. Romano
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2042218607