Magnetism and superconductivity in CeRh_{1-x}Ir_xIn_5 heavy fermion materials

TL;DR

This study investigates the coexistence of magnetism and superconductivity in CeRh_{1-x}Ir_xIn_5 heavy fermion compounds using muon spin relaxation, revealing microscopic coexistence in some compositions and purely superconducting behavior in others.

Contribution

It provides experimental evidence of microscopic coexistence of magnetism and superconductivity in CeRh_{1-x}Ir_xIn_5, expanding understanding of heavy fermion materials.

Findings

Superconducting compositions show no magnetic moments.

Antiferromagnetic and superconducting phases coexist in x=0.5.

Magnetism and superconductivity coexist microscopically in CeRh_{0.5}Ir_{0.5}In_5.

Abstract

We report on zero-field muon spin relaxation studies of cerium based heavy-fermion materials CeRh_{1-x}Ir_xIn_5. In the superconducting x=0.75 and 1 compositions muon spin relaxation functions were found to be temperature independent across T_c; no evidence for the presence of electronic magnetic moments was observed. The x=0.5 material is antiferromagnetic below T_N=3.75 K and superconducting below T_c=0.8 K. Muon spin realxation spectra show the gradual onset of damped coherent oscillations characteristic of magnetic order below T_N. At 1.65 K the total oscillating amplitude accounts for at least 85% of the sample volume. No change in muon precession frequency or amplitude is detected on cooling below T_c, indicating the microscopic coexistence of magnetism and superconductivity in this material.