Effects of Pressure and Doping on Ruddlesden-Popper phases Lan+1NinO3n+1

TL;DR

This study explores how pressure and chemical doping influence the electronic and superconducting properties of Ruddlesden-Popper nickelates, revealing pressure-induced superconductivity up to 86 K in La3Ni2O7.

Contribution

It systematically investigates the effects of pressure and doping on Ruddlesden-Popper phases, highlighting conditions that induce high-temperature superconductivity.

Findings

Pressure induces superconductivity up to 86 K in La3Ni2O7.

No superconductivity observed in La2NiO4 and La4Ni3O10 under high pressure.

Doping and pressure effectively tune transport properties of these phases.

Abstract

Recently the discovery of superconductivity with a critical temperature Tc up to 80 K in Ruddlesden-Popper phases Lan+1NinO3n+1 (n = 2) under pressure has garnered considerable attention. Up to now, the superconductivity was only observed in La3Ni2O7 single crystal grown with the optical-image floating zone furnace under oxygen pressure. It remains to be understood the effect of chemical doping on superconducting La3Ni2O7 as well as other Ruddlesden-Popper phases. Here, we systematically investigate the effect of external pressure and chemical doping on polycrystalline Ruddlesden-Popper phases. Our results demonstrate the application of pressure and doping effectively tunes the transport properties of Ruddlesden-Popper phases. We find pressure-induced superconductivity up to 86 K in La3Ni2O7 polycrystalline sample, while no signatures of superconductivity are observed in La2NiO4 and La4Ni3O10 systems under high pressure up to 50 GPa. Our study sheds light on the exploration of high-Tc superconductivity in nickelates.