| Abstract Scope |
Two-dimensional ferrovalley materials combine intrinsic magnetism with valley polarization, enabling nonvolatile valley-based memory, filters, and logic. Here, we report a first-principles computational discovery of rare-earth iodide monolayers, RI2 (R = Sc, Y, La-Lu), as a chemically rich family of ferrovalley materials. Unconstrained crystal-structure prediction using kinetically limited minimization, combined with prototype sampling, identifies layered bulk phases analogous to transition-metal dichalcogenides, including 2H, 1T, and 1Td polytypes. Calculated decomposition and exfoliation energetics indicate thermodynamic stability and feasible mechanical exfoliation. In the 2H monolayer phase, rare-earth d and f electrons drive ferromagnetism, while spin-orbit coupling lifts the K/K' valley degeneracy and produces spontaneous valley polarization ranging from 15 to 143 meV without external fields. The valley polarization is strain tunable, and Berry-curvature calculations reveal an anomalous valley Hall response. These results establish RI2 monolayers as promising candidates for valleytronic information storage and processing. |