Structural transition, electric transport, and electronic structures in the compressed trilayer nickelate La4Ni3O10

TL;DR

This study investigates the structural and electronic changes in La4Ni3O10 under high pressure, revealing a phase transition and potential superconductivity mechanisms relevant to nickelate superconductors.

Contribution

It provides the first detailed analysis of pressure-induced structural transition and electronic evolution in La4Ni3O10, linking these changes to possible superconductivity.

Findings

Structural transition from monoclinic to tetragonal around 12.6-13.4 GPa

Ni 3dz2 orbital crossing the Fermi level at high pressure

Resistance drops below 7 K indicating possible superconductivity

Abstract

Atomic structure and electronic band structure are fundamental properties for understanding the mechanism of superconductivity. Motivated by the discovery of pressure-induced high-temperature superconductivity at 80 K in the bilayer Ruddlesden-Popper nickelate La3Ni2O7, the atomic structure and electronic band structure of the trilayer nickelate La4Ni3O10 under pressure up to 44.3 GPa are investigated. A structural transition from the monoclinic P21/a space group to the tetragonal I4/mmm around 12.6-13.4 GPa is identified, accompanying with a drop of resistance below 7 K. Density functional theory calculations suggest that the bonding state of Ni 3dz2 orbital rises and crosses the Fermi level at high pressures, which may give rise to possible superconductivity observed in resistance under pressure in La4Ni3O10. The trilayer nickelate La4Ni3O10 shows some similarities with the bilayer La3Ni2O7 and has unique properties, providing a new platform to investigate the underlying mechanism of superconductivity in nickelates.