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, particularly along the c axis, enhances the spin density wave transition temperature, and elevates the pressure required for the orthorhombic-to-tetragonal structural transition. Superconductivity is observed across all doping levels under high pressures, with the onset Tc rising to ∼93~K for x=2.1 and 2.4 from the electronic transport measurement. Using the radio-frequency transmission technique, newly applied to nickelate superconductors, we detect signatures of superconductivity at 98±2~K in the x=2.4 compound, pushing the Tc frontier further. We identify a universal linear relationship where Tc decreases with the c-axis lattice parameter at a rate of approximately −28~K/\AA, demonstrating that enhanced interlayer magnetic exchange coupling is the dominant mechanism for superconducting pairing. Our work establishes the critical role of magnetism and provides a unified structural descriptor for elevating Tc in bilayer nickelates.
@article{arxiv.2510.12359,
title = {Interlayer coupling enhanced superconductivity near 100 K in La$_{3-x}$Nd$_x$Ni$_2$O$_7$},
author = {Zhengyang Qiu and Junfeng Chen and Dmitrii V. Semenok and Qingyi Zhong and Di Zhou and Jingyuan Li and Peiyue Ma and Xing Huang and Mengwu Huo and Tao Xie and Xiang Chen and Ho-kwang Mao and Viktor Struzhkin and Hualei Sun and Meng Wang},
journal= {arXiv preprint arXiv:2510.12359},
year = {2025}
}