Enhanced superconductivity and mixed-dimensional behaviour in infinite-layer samarium nickelate thin films

作者：Mingwei Yang, Hao Wang, Jiayin Tang, Junping Luo, Xianfeng Wu, Wenjing Xu, Aile Wang, Yuetong Wu, Ruilin Mao, Ze Wang, Zhicheng Pei, Guangdi Zhou, Zhengang Dong, Bohan Feng, Lingchi Shi, Wenjie Meng, Chuanying Xi, Li Pi, Qingyou Lu, J. Okamoto, Hsiao-Yu Huang, D. J. Huang, Haoliang Huang, Q S Wang, Peng Gao, Zhuoyu Chen, Danfeng Li · 发表于：Nature Communications · 年份：2026 · DOI：10.1038/s41467-026-69650-3 · 被引用次数：2 · 研究领域：Iron-based superconductors research、Magnetic and transport properties of perovskites and related materials、Electronic and Structural Properties of Oxides

Rare-earth infinite-layer nickelates are emerging unconventional superconductors, with materials synthesis largely limited to early lanthanide compounds. Here, we report phase-pure samarium-based nickelate thin films on (LaAlO3)0.3(Sr2TaAlO6)0.7 (001) substrates, including the first demonstration of Sm1-xSrxNiO2. Co-doped compounds achieve a record-small c-axis parameter (3.26 Å) and superconducting transitions up to 32.5 K, revealing a clear correlation between decreasing c-axis parameter and increasing critical temperature across different rare-earth systems. Angle-dependent magnetoresistance shows a hybrid 2D/3D superconductivity with enhanced rare-earth 5d–Ni 3 d orbital coupling, confirmed by resonant inelastic X-ray scattering. In addition, increasing Eu concentration drives a shift toward 3D superconductivity, and Eu-containing samples exhibit distinctive negative magnetoresistance even in the superconducting state. These findings advocate clear materials design principles for higher transition temperatures and exotic physics in infinite-layer nickelate superconductors through structural engineering of the rare-earth site. The authors report the synthesis and characterization of samarium-based superconducting infinite layer nickelate thin films, along with co-doped variants incorporating europium and calcium. The co doped compounds achieve a record-small c-axis parameter and display superconducting transition temperatures up to 32.5 K.