Inductive-Effect-Driven Tunability of Magnetism and Lumines-cence in Triangular Layers ANd(SO4)2 (A = Rb, Cs)

Tuning the energy landscape of manybody electronic states in extended solids through the inductive effect-a concept widely used in organic chemistry-offers a new, effective strategy for materials development. Here, we demonstrate this approach using the ANd(SO4)2 (A = Rb, Cs) model system, which possesses different A-site electronegativity and displays a distorted triangular lattice of Nd3+ (4I9/2 ground term). Magnetization data indicate appreciable antiferromagnetic interactions without long-range ordering down to 1.8 K while highlighting the tunable population of the electronic states. Temperature-dependent and time-resolved photoluminescence measurements reveal that emissions and nonradiative processes can be modified by the inductive effect at the atomic level. Heat capacity data confirm no magnetic ordering and add insight into the role of phonons in emission lifetime. Density functional theory calculations prove enhanced covalency in the Cs compound compared to the Rb counterpart while acknowledging the adjustable magnetic intralayer and inter-layer exchange pathways. These results demonstrate a viable framework for utilizing the inductive effect as an important knob for simultaneously dialing in magnetic, optical, and electronic properties in quantum materials.