Magnetic Order in A Quenched-High-Temperature-Phase of Cu-Doped MnBi

TL;DR

This study explores the magnetic properties of Cu-doped MnBi in a quenched high-temperature phase, revealing a new trigonal structure and complex magnetic ordering, which could impact permanent magnet development.

Contribution

It reports the synthesis of Cu-doped MnBi with a novel trigonal structure and characterizes its high-temperature antiferromagnetic and low-temperature ferromagnetic/ferrimagnetic phases.

Findings

Discovery of a new trigonal structure in Cu-doped MnBi.

Identification of high-temperature AFM and low-temperature FM/FiM ordering.

Establishment of a magnetic phase diagram related to Cu doping.

Abstract

Permanent magnets are of great importance due to their vast applications. MnBi has been proposed to be a potential permanent magnet that can be widely used while past efforts have been focused on optimizing the ferromagnetic low-temperature phase of MnBi. Herein, we report a series of new materials, CuxMn1-xBi, crystallizing in a quenched high-temperature-phase (QHTP) MnBi-related structure. We synthesized single crystals of CuxMn1-xBi and found that they crystallize in an unreported trigonal structure (P -31c). Magnetic properties measurements imply high-temperature antiferromagnetic (AFM) ordering and low-temperature ferromagnetic or ferrimagnetic (FM/FiM) ordering. By analyzing the doping effect on crystal structure and magnetic properties, we established a magnetic phase diagram for Cu-doped MnBi and attributed the AFM and FM/FiM to two different atomic sites of Mn.