Superconductivity in Freestanding Infinite-Layer Nickelate Membranes.

Yan, Shengjun; Mao, Wei; Sun, Wenjie; Li, Yueying; Sun, Haoying; Yang, Jiangfeng; Hao, Bo; Guo, Wei et al. · Adv Mater · 2024

basic_science · Level V

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Abstract

The observation of superconductivity in infinite-layer nickelates has attracted significant attention due to its potential as a new platform for exploring high-T<sub>c</sub> superconductivity. However, thus far, superconductivity has only been observed in epitaxial thin films, which limits the manipulation capabilities and modulation methods compared to two-dimensional exfoliated materials. Given the exceptionally giant strain tunability and stacking capability of freestanding membranes, separating superconducting nickelates from the as-grown substrate is a novel way to engineer the superconductivity and uncover the underlying physics. Herein, this work reports the synthesis of the superconducting freestanding La<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>2</sub> membranes ( <math xmlns="http://www.w3.org/1998/Math/MathML"> <semantics> <mrow><msubsup><mi>T</mi> <mi>c</mi> <mi>zero</mi></msubsup> <mspace></mspace> <mo>=</mo> <mspace></mspace> <mn>10.6</mn> <mspace></mspace> <mi>K</mi></mrow> <annotation>${T}_{\mathrm{c}}^{\mathrm{zero}}\ =\ 10.6\ \mathrm{K}$</annotation></semantics> </math> ), emphasizing the crucial roles of the interface engineering in the precursor phase film growth and the quick transfer process in achieving superconductivity. This work offers a new versatile platform for investigating superconductivity in nickelates, such as the pairing symmetry via constructing Josephson tunneling junctions and higher T<sub>c</sub> values via high-pressure experiments.