Stripe segregation and magnetic coupling in the nickelate La_5/3 Sr_1/3 NiO_4

TL;DR

This study uses advanced computational methods to explore how stripe formation influences the structure and electronic properties of La5/3Sr1/3NiO4, revealing interactions between structural, magnetic, and electronic degrees of freedom.

Contribution

It provides new insights into the interplay of stripe segregation, magnetic coupling, and structural distortions in nickelates using DFT and LDA+U methods.

Findings

Stripe segregation is induced by magnetic interactions.

Octahedral distortions are crucial for insulating behavior.

Structural and electronic degrees of freedom are strongly coupled.

Abstract

We investigate the consequences of the stripe formation in the nickelate La5/3Sr1/3NiO4 for the details of its crystal structure and electronic states. Our data are based on numerical simulations within density functional theory (DFT) and the generalized gradient approximation (GGA). The on-site Coulomb interaction is included in terms of the LDA+U scheme. Structure optimization of preliminary experimental data indicates a strong interaction between the structural and electronic degrees of freedom. In particular, we find a segregation of the diagonal filled stripes induced by a delicate interplay with the magnetic coupling. Beyond the cooperative effect of stripe segregation and spin order, distinct octahedral distortions are essential for the formation of an insulating state.