Bulk superconductivity up to 96 K in pressurized nickelate single crystals
Article Date: 02 December 2025
Article URL: https://www.nature.com/articles/s41586-025-09954-4
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Summary
The team reports bulk superconductivity up to an onset temperature of 96 K in bilayer nickelate single crystals (La2SmNi2O7-δ and related compositions) when placed under high pressure. Crucially, the crystals were grown at ambient pressure using a flux method and show high homogeneity and crystallinity. Electrical transport and magnetic measurements provide evidence for zero resistivity and the Meissner effect under pressure. Structural studies under low temperature and high pressure show that both monoclinic and tetragonal phases can host superconductivity. The authors also correlate higher Tc under pressure with larger in-plane lattice distortion at ambient conditions, and demonstrate a pathway to higher transition temperatures in this family of nickelates.
Key Points
- Bulk superconductivity observed in bilayer nickelate single crystals grown at ambient pressure.
- Maximum reported onset Tc up to 96 K under high pressure (La1.57Sm1.43Ni2O7-δ).
- Zero resistivity and Meissner effect measured, confirming bulk superconducting behaviour (example: Tc,max onset = 92 K, Tc,max zero = 73 K at 21 GPa; Meissner Tc ≈ 60 K at 20.6 GPa).
- High-quality flux-grown crystals validated by EDS, single-crystal XRD, NQR and STEM; samples are highly homogeneous.
- Both monoclinic and tetragonal structures can support superconductivity in this bilayer nickelate.
- Authors find a correlation between larger in-plane lattice distortion at ambient conditions and higher Tc under pressure.
- The work addresses reproducible single-crystal growth without high oxygen-pressure methods and maps a route towards higher Tc in nickelates.
Content summary
La2SmNi2O7-δ single crystals were synthesised by a flux method at ambient pressure and characterised thoroughly to demonstrate composition and structural uniformity. Under applied pressures above ~14 GPa the crystals develop superconductivity with clear bulk signatures: resistivity drops to zero and magnetic susceptibility shows Meissner screening. Low-temperature high-pressure structural measurements reveal that superconductivity appears in both monoclinic and tetragonal variants of the bilayer nickelate, indicating structural flexibility for the superconducting phase.
The authors show that specimens with larger in-plane lattice distortion at ambient pressure tend to reach higher Tc when pressurised; exploiting this correlation they report an onset Tc of 96 K in La1.57Sm1.43Ni2O7-δ. The paper emphasises overcoming previous limitations in reproducible crystal growth and clarifies structural aspects of the superconducting state.
Context and relevance
This result is important for the high-temperature superconductivity field because it raises the transition temperature in nickelates closer to liquid-nitrogen temperatures under pressure and demonstrates bulk superconductivity in well-characterised single crystals produced without extreme oxygen-pressure growth. It links crystallographic distortion to Tc, offering a materials-design handle for raising transition temperatures. The finding is relevant for researchers working on unconventional superconductors, materials synthesis, high-pressure physics and anyone tracking progress towards higher-Tc, more practical superconductors.
Why should I read this?
Short and blunt: if you care about high-Tc materials or nickelates specifically, this paper is a proper headline — bulk crystals, grown at normal pressures, showing superconductivity up to 96 K under pressure. They also pin down structure–Tc connections and make the growth reproducible, so it isn’t just a flaky, one-off claim. Read it if you want to know where nickelate superconductors stand now and what practical knobs (structure, composition, pressure) push Tc up.
Author style
Punchy: the authors deliver a high-impact advance — reproducible ambient-pressure crystal growth, convincing bulk superconductivity measurements and a clear structural/Tc correlation. For specialists, this amplifies the significance: it’s not just another pressure result but a credible, repeatable materials route that moves nickelates forward toward higher transition temperatures.