How chemical pressure affects the fundamental properties of rare-earth pnictides: an ARPES view

TL;DR

This study uses ARPES and theoretical calculations to explore how chemical pressure influences the electronic and magnetic properties of rare-earth pnictides, revealing different hybridization mechanisms and magnetic behaviors.

Contribution

It provides new insights into the electronic structure and magnetic interactions in CeFePO and CeFeAs_0.7P_0.3O under chemical pressure, highlighting distinct orbital contributions.

Findings

Ferromagnetism in CeFeAs_0.7P_0.3O is mainly mediated by Fe 3d_xz/yz orbitals.

Kondo screening in CeFePO involves strong interaction of Fe 3d_3z^2-r^2 orbitals.

Differences in Fe-derived band structures imply varied hybridization mechanisms.

Abstract

Angle-resolved photoelectron spectroscopy, supplemented by theoretical calculations has been applied to study the electronic structure of heavy-fermion material CeFePO, a homologue to the Fe-based high-temperature superconductors, and CeFeAs_0.7P_0.3O, where the applied chemical pressure results in a ferromagnetic order of the 4f moments. A comparative analysis reveals characteristic differences in the Fe-derived band structure for these materials, implying a rather different hybridization of valence electrons to the localized 4f orbitals. In particular, our results suggest that the ferromagnetism of Ce moments in CeFeAs_0.7P_0.3O is mediated mainly by Fe 3d_xz/yz orbitals, while the Kondo screening in CeFePO is instead due to a strong interaction of Fe 3d_3z^2-r^2 orbitals.