Influence of strain on the properties of CeRuPO and CeOsPO Kondo systems

TL;DR

This study examines how isotropic strain affects the magnetic ground state and Fermi surface of CeRuPO and CeOsPO Kondo systems, revealing strain and electronic structure as key factors.

Contribution

It provides ab-initio insights into how strain influences magnetic properties and Fermi surface topology in structurally similar Kondo systems.

Findings

Strain significantly impacts magnetic ground states.

Differences in Fermi surface are crucial for magnetic behavior.

Effective U parameter influences magnetic phase stability.

Abstract

We investigated the influence of isotropic strain on the type of the magnetic ground-state and the Fermi surface for the structurally-equivalent CeRuPO and CeOsPO crystals with slightly different lattice parameters. The two systems exhibit different magnetic orderings at zero strain. According to the phase diagram of CeRuPO under pressure the difference might be due to the different Ce-Ce inter-atomic distances. We applied {\it ab-initio} calculations based on the density-functional theory and the generalized-gradient approximation with an additional Coulomb repulsion (GGA+$U$), which indeed reveal a significant impact of the strain and the effective $U$ parameter on the magnetic ground state. However, it is demonstrated that the difference is more likely related to the details in the Fermi surface.