High-temperature superconductivity at 100K in La3-xNdxNi2O7.

Systematically controlling the superconducting transition temperature (Tc) in the bilayer Ruddlesden-Popper nickelate La3Ni2O7 remains a significant challenge. Here, we address this by synthesizing high-quality polycrystalline La3-xNdxNi2O7 (0 ≤ x ≤ 2.4) with record-level rare-earth substitution. Nd doping compresses the lattice and enhances the spin density wave (SDW) transition temperature, and elevates the pressure required for the orthorhombic-to-tetragonal structural transition. Superconductivity is observed across all doping levels in high-pressure electronic transport measurements, with the onset Tc rising to ~ 93 K and the resistance derivative indicating the signature of superconductivity reaching 96-97 K for x = 2.1 and 2.4. Using the radio-frequency transmission technique, recently applied to nickelate superconductors, we detect signatures of superconductivity at 100.5 K in the x = 2.1 compound, pushing the Tc frontier further. Our work reveals the critical role of magnetism and provides a structural descriptor for elevating Tc in Ruddlesden-Popper nickelates.