Net Magnetization and Inhomogeneous Magnetic Order in a High-Tc Nickelate Superconductor

Alexander J. Grutter; Nurul Fitriyah; Brian B. Maranville; Saurav Prakash; Andreas Suter; Jochen Stahn; Gianluca Janka; Xing Gao; King Yau Yip; Zaher Salman; Thomas Prokscha; Julie A. Borchers; Ariando Ariando

arXiv · 2512.18005

Net Magnetization and Inhomogeneous Magnetic Order in a High-Tc Nickelate Superconductor

Alexander J. Grutter·Nurul Fitriyah·Brian B. Maranville·Saurav Prakash·Andreas Suter·Jochen Stahn·Gianluca Janka·Xing Gao·King Yau Yip·Zaher Salman·Thomas Prokscha·Julie A. Borchers·Ariando Ariando

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Abstract

High-temperature and high-magnetic-field-induced re-entrant superconductivity has been discovered in the infinite-layer nickelate $\mathrm{Sm_{1-x-y} Eu_x Ca_y Ni O_2}$ (SECNO). Infinite-layer nickelates are the closest known analogues of high-$\mathrm{T}_c$ cuprate superconductors, yet they host distinct magnetic ground states. Using low-energy muon spin relaxation and polarized neutron reflectometry, we reveal the magnetic order in SECNO. We find that magnetic freezing occurs at a higher-temperature than in other nickelate compounds, and that a substantial net magnetization of 55 $\,\mathrm{kA}\,\mathrm{m}^{-1}$ $\pm10 \,\mathrm{kA}\,\mathrm{m}^{-1}$ emerges and remains largely unchanged across the superconducting transition. The magnetism in SECNO is disordered and nonuniform.

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Alexander J. Grutter, Nurul Fitriyah, Brian B. Maranville, Saurav Prakash, Andreas Suter, Jochen Stahn, Gianluca Janka, Xing Gao, King Yau Yip, Zaher Salman, Thomas Prokscha, Julie A. Borchers, Ariando Ariando. 2025-12-19. Net Magnetization and Inhomogeneous Magnetic Order in a High-Tc Nickelate Superconductor. https://arxiv.org/abs/2512.18005

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