Year: 2005
Type: article
Abstract: The compositional ordering of Ag, Pb, Sb, Te ions in ${(\mathrm{Ag}\mathrm{Sb}{\mathrm{Te}}_{2})}_{x}{(\mathrm{Pb}\mathrm{Te})}_{2(1\ensuremath{-}x)}$ systems possessing a NaCl structure is studied using a Coulomb lattice gas (CLG) model on a face-centered cubic (fcc) lattice and Monte Carlo simulations. Our results show different possible microstructural orderings. Ordered superlattice structures formed out of $\mathrm{Ag}\mathrm{Sb}{\mathrm{Te}}_{2}$ layers separated by ${\mathrm{Pb}}_{2}{\mathrm{Te}}_{2}$ layers are observed for a large range of $x$ values. For $x=0.5$, we see an array of tubular structures formed by $\mathrm{Ag}\mathrm{Sb}{\mathrm{Te}}_{2}$ and ${\mathrm{Pb}}_{2}{\mathrm{Te}}_{2}$ blocks. For $x=1$, $\mathrm{Ag}\mathrm{Sb}{\mathrm{Te}}_{2}$ has a body-centered tetragonal (bct) structure which is in agreement with previous Monte Carlo simulation results for restricted primitive model (RPM) at closed packed density. The phase diagram of this frustrated CLG system is discussed.
Source: Physical Review B
Authors: Khang Hoang, Keyur Desai, S. D. Mahanti
Institution: Michigan State University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2012386141