Interplay between Superconductivity and Magnetism in Rb0.8Fe1.6Se2 under Pressure

TL;DR

This study investigates how pressure affects superconductivity and magnetism in Rb0.8Fe1.6Se2, revealing a strong link between magnetic order and the suppression of superconductivity without structural phase changes.

Contribution

It provides new insights into the pressure-induced magnetic and electronic changes in Rb0.8Fe1.6Se2, highlighting the correlation between antiferromagnetism and superconductivity.

Findings

Superconductivity decreases with pressure, disappearing near 6 GPa.

No structural phase transition observed up to 15.6 GPa.

Emergence of a paramagnetic phase correlates with loss of superconductivity.

Abstract

High-pressure magnetization, structural and 57Fe M\"ossbauer studies were performed on superconducting Rb0.8Fe1.6Se2.0 with Tc = 32.4 K. The superconducting transition temperature gradually decreases on increasing pressure up to 5.0 GPa followed by a marked step-like suppression of superconductivity near 6 GPa. No structural phase transition in the Fe vacancy-ordered superstructure is observed in synchrotron XRD studies up to 15.6 GPa, while the M\"ossbauer spectra above 5 GPa reveal the appearance of a new paramagnetic phase and significant changes in the magnetic and electronic properties of the dominant antiferromagnetic phase, coinciding with the disappearance of superconductivity. These findings underline the strong correlation between antiferromagnetic order and superconductivity in phase-separated AxFe2-x/2Se2 (A = K, Rb, Cs) superconductors.