Hydrostatic and chemical pressure tuning of CeFeAs_1-xP_xO single crystals

TL;DR

This study explores how hydrostatic and chemical pressure influence magnetic properties and superconductivity in CeFeAs_1-xP_xO single crystals, revealing a complex interplay between magnetism and superconductivity.

Contribution

It provides new insights into the relationship between Ce and Fe magnetism and superconductivity under combined pressure and substitution in CeFeAsO compounds.

Findings

Fe magnetism weakens with pressure

Ce moments switch from antiferromagnetic to ferromagnetic at 1.95 GPa

Superconductivity is suppressed by Ce magnetism

Abstract

We carried out a combined P-substitution and hydrostatic pressure study on CeFeAs_1-xP_xO single crystals in order to investigate the peculiar relationship of the local moment magnetism of Ce, the ordering of itinerant Fe moments, and their connection with the occurrence of superconductivity. Our results evidence a close relationship between the weakening of Fe magnetism and the change from antiferromagnetic to ferromagnetic ordering of Ce moments at p*=1.95 GPa in CeFeAs_0.78P_0.22O. The absence of superconductivity in CeFeAs_0.78P_0.22O and the presence of a narrow and strongly pressure sensitive superconducting phase in CeFeAs_0.70P_0.30O and CeFeAs_0.65P_0.35O indicate the detrimental effect of the Ce magnetism on superconductivity in P-substituted CeFeAsO.