High-temperature superconductivity at 100K in La<sub>3-x</sub>Nd<sub>x</sub>Ni<sub>2</sub>O<sub>7</sub>.

Qiu, Zhengyang; Chen, Junfeng; Semenok, Dmitrii V; Zhong, Qingyi; Zhou, Di; Li, Jingyuan; Ma, Peiyue; Huang, Xing et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Systematically controlling the superconducting transition temperature (T<sub>c</sub>) in the bilayer Ruddlesden-Popper nickelate La<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub> remains a significant challenge. Here, we address this by synthesizing high-quality polycrystalline La<sub>3-x</sub>Nd<sub>x</sub>Ni<sub>2</sub>O<sub>7</sub> (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 T<sub>c</sub> 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 T<sub>c</sub> frontier further. Our work reveals the critical role of magnetism and provides a structural descriptor for elevating T<sub>c</sub> in Ruddlesden-Popper nickelates.