# Doping Mn into (Li1-xFex)OHFe1-ySe superconducting crystals via ion-exchange and ion-release/introduction syntheses

## TL;DR

This study demonstrates effective Mn doping into (Li1-xFex)OHFe1-ySe superconductors via hydrothermal methods, revealing minimal impact on superconductivity but significant changes in electronic properties, aiding understanding of band contributions.

## Contribution

It introduces hydrothermal ion-exchange and ion-release methods for Mn doping in (Li1-xFex)OHFe1-ySe superconductors, enabling detailed studies of electronic band effects.

## Key findings

- Mn doping is successfully incorporated into the lattice.
- Superconducting transition temperature remains largely unaffected.
- Hole carrier contribution is significantly altered by Mn doping.

## Abstract

We report the success in introducing Mn into (Li1-xFex)OHFe1-ySe superconducting crystals by applying two different hydrothermal routes, ion exchange (1-Step) and ion release/introduction (2-Step). The micro-region x-ray diffraction and energy dispersive x-ray spectroscopy analyses indicate that the Mn has been doped into the lattice, and its content in the 1-Step fabricated sample is higher than that in the 2-Step one. Magnetic susceptibility and electric transport properties reveal that Mn doping influences little on the superconducting transition, regardless of 1-Step or 2-Step routes. By contrast, the characteristic temperature, T*, where the negative Hall coefficient reaches its minimum, is significantly reduced by Mn doping. This implies that the reduction of the hole carriers contribution is obviously modified, and hence the hole band might have no direct relationship with the superconductivity in (Li1-xFex)OHFe1-ySe superconductors. Our present hydrothermal methods of ion exchange and ion release/introduction provide an efficient way for elements substitution/doping into (Li1-xFex)OHFe1-ySe superconductors, which will promote the in-depth investigations on the role of multiple electron and hole bands and their interplay with the high-temperature superconductivity in the FeSe-based superconductors.

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Source: https://tomesphere.com/paper/1704.00245