Charge correlations and magnetoelastic coupling in intercalated transition metal dichalcogenides

Intercalating magnetic atoms into layered transition metal dichalcogenides provides a powerful route to engineer intertwined electronic and magnetic states. Using angle-resolved photoemission, X-ray scattering, magnetometry, and first-principles calculations, we uncover the origin of charge correlations in Fe- and Co-intercalated TaS₂ and NbS₂. While Ta-based compounds exhibit only short-range charge fluctuations, Fe₀.₃₅NbS₂ develops long-range charge order concomitant with antiferromagnetism and enhanced by magnetic field. By ruling out Fermi-surface nesting and conventional electron--phonon coupling, we show that this charge order is stabilized by strong magnetoelastic coupling, establishing magnetic intercalation as a route to tune spin-lattice-charge entanglement in van der Waals materials.