Hybrid Spin-Crossover Superatomic Crystals for Novel Switchable Materials

Superatoms are atomically precise molecular building blocks which have been used to create materials that show magnetic ordering, crystalline thermal conductivity, and thermally activated electrical transport. Recent studies have shown that structural phase transitions in superatomic crystals can directly impact the optical band gap and thermal and electronic conductivity of the materials, but it is difficult to design further phase transitions using current supertomic systems. Meanwhile, spin crossover is a well-understood phase transition in many divalent iron complexes where a switch from low-spin to high-spin occurs in response to irradiation, temperature, and pressure. This spin crossover also produces a physical expansion of the iron sites - a structural phase transition which could be used to induce changes in the properties of superatomic crystals. My proposal therefore aims to combine superatomic cluster building blocks with spin crossover iron sites to create novel phase transition materials with switchable properties.