Kavli Affiliate: Kwabena Bediako| Summary:Van der Waals hosts intercalated with transition metal (TM) ions exhibit a range of magnetic properties strongly influenced by the structural order of the intercalants. However, predictive computational models for the intercalant ordering phase diagram are lacking, complicating experimental pursuits to target key structural phases. Here we use Density Functional Theory (DFT) to construct a pairwise lattice model and Monte Carlo to determine its associated thermodynamic phase diagram. To circumvent the complexities of modeling magnetic effects, we use the diamagnetic ions Zn$^2+$ and Sc$^3+$ as computationally accessible proxies for divalent and trivalent species of interest (Fe$^2+$ and Cr$^3+$), which provide insights into the high-temperature thermodynamic phase diagram well above the paramagnetic transition temperature. We find that electrostatic coupling between intercalants is almost entirely screened, so the pairwise lattice model represents a coarse-grained charge density reorganization about the intercalated sites. The resulting phase diagram reveals that the entropically-favored $sqrt3 times sqrt3$ ordering and coexisting locally ordered $sqrt3 times sqrt3$ and $2 times 2$ domains persist across a range of temperatures and intercalation densities. This occurs even at quarter filling of interstitial sites (corresponding to bulk stoichiometries of M$_0.25$TaS$_2$; M = intercalant ion) where a preference for long-range $2 times 2$ order is typically assumed.| Search Query: arXiv Query: search_query=au:”bediako kwabena”&id_list=&start=0&max_results=10Read More