Superconductivity in an infinite-layer nickelate superlattice.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Superconductivity in infinite-layer nickelates is a recent discovery offering insights into high-temperature superconductivity.
• Defects in doped nickelate films hinder superconductivity, limiting research to heterostructures.
• Superlattices of ultrathin nickelates are underexplored, impeding interface effect studies and higher critical temperature exploration.

Purpose of the Study:

• To demonstrate superconducting infinite-layer nickelate superlattices using topotactic reduction.
• To investigate the critical thickness for achieving high-quality superlattices.
• To explore the interface effect on superconductivity in nickelate superlattices.

Main Methods:

• Fabrication of infinite-layer nickelate superlattices [(Nd0.8Sr0.2NiO2)8/(SrTiO3)2]10 via topotactic reduction.
• Structural characterization to determine the critical thickness for superlattice formation.
• Measurement of superconducting properties, including critical temperature (Tc) and dimensionality.

Main Results:

• High-quality superlattices were achieved only above a critical thickness, dependent on the nickelate layer.
• The superconducting superlattice exhibited a critical temperature (Tc) of 12.5 K.
• A two-dimensional superconducting feature was observed, indicating intrinsic superconductivity.

Conclusions:

• The successful fabrication of superconducting infinite-layer nickelate superlattices opens new avenues for research.
• This work facilitates the study of interface effects and multilevel interface engineering in infinite-layer nickelates.
• The findings contribute to understanding the superconducting mechanism and exploring higher critical temperatures.