Exotic Magnetic Properties of High-Entropy Ruddlesden–Popper Perovskite Single Crystals

Ruddlesden–Popper perovskites have long been studied as prototype strongly correlated electron systems, exhibiting exotic phenomena such as high-temperature superconductivity. High-entropy engineering expands the compositional space of these materials, offering enhanced properties such as chemical stability and tunable thermal expansion. However, prior studies have focused solely on powder samples, limiting understanding of their intrinsic properties. Here, we report the first single-crystal growth of a high-entropy Ruddlesden–Popper perovskite, La₁.₀₄Sr₀.₉₆(Ti₀.₂₂Mn₀.₀₆Fe₀.₂₁Co₀.₃₂Ni₀.₁₉)O₄, synthesized by the floating-zone method. Heat-capacity and magnetic-susceptibility measurements reveal short-range magnetic ordering at low temperature, consistent with a cluster spin-glass state. Magnetization data show pronounced hysteresis with a remanent moment of ~0.07 μ_B, indicating a canted spin structure inconsistent with G-type antiferromagnetism. These findings demonstrate that high-entropy design enables tuning of exchange interactions and stabilization of unconventional magnetic phases in layered oxides.