Data-Driven Discovery of Composition–Structure–Property Relationship in Novel Wave-Transparent High-Entropy Rare Earth Disilicate

Developing advanced materials with simultaneously excellent wave transparency and efficient thermal insulation is critical for hypersonic vehicles. While rare earth disilicates (RE 2 Si 2 O 7 ) are promising candidates, their vast chemical space and complex polymorphism hinder precise property modulation. Herein, we establish an integrated high-throughput experimental and machine learning strategy to systematically investigate the composition–structure–property relationship of high-entropy RE 2 Si 2 O 7 . The results demonstrate that the average RE 3+ ionic radius determines the phase boundary. Notably, Sc incorporation jointly reduces both the dielectric constant and thermal conductivity. Specifically, the small size and strong electron localization of Sc minimize the polarizability, while its severe size and mass mismatch with other RE elements intensify phonon scattering. The model’s generalization is further validated by designing a series of high-entropy RE 2 Si 2 O 7 containing 5 to 9 distinct RE elements. Ultimately, the (Ho 1/5 Tm 1/5 Yb 1/5 Lu 1/5 Sc 1/5 ) 2 Si 2 O 7 high-entropy ceramic achieves a low dielectric constant ( ε = 5.4) and a low thermal conductivity ( κ = 1.3 W·m −1 ·K −1 ). This data-driven strategy provides a new pathway for the rational design of advanced high-entropy wave-transparent materials for extreme environments.