Stability Frontiers and Mixed-Dimensional Physics in the Kagome Intermetallics <i>Ln</i> ₃ScBi₅ (<i>Ln</i> = La–Nd, Sm)

Abstract Low-dimensional physics provides profound insights into strongly correlated interactions, leading to enhanced quantum effects and the emergence of exotic quantum states. The Ln 3 ScBi 5 family stands out as a chemically versatile kagome platform with mixed low-dimensional structural framework and tunable physical properties. Our research initiates with a comprehensive evaluation of the currently known Ln 3 ScBi 5 ( Ln = La–Nd, Sm) materials, providing a robust methodology for assessing their stability frontiers within this system. Focusing on Pr 3 ScBi 5 , we investigate the influence of the zigzag chains of quasi-one-dimensional (Q1D) motifs and the distorted kagome layers of quasi-two-dimensional (Q2D) networks in the mixed-dimensional structure on the intricate magnetic ground states and unique spin fluctuations. Our study reveals that the noncollinear antiferromagnetic (AFM) moments of Pr 3+ ions are confined within the Q2D kagome planes, displaying minimal in-plane anisotropy. In contrast, a strong AFM coupling is observed within the Q1D zigzag chains, significantly constraining spin motion. Notably, magnetic frustration is partially a consequence of coupling to conduction electrons via Ruderman–Kittel–Kasuya–Yosida interaction, highlighting a promising framework for future investigations into mixed-dimensional frustration in Ln 3 ScBi 5 systems.