MnRhBi3: A Cleavable Antiferromagnetic Metal

TL;DR

This study introduces MnRhBi3 as a cleavable antiferromagnetic metal with potential for spintronic applications, demonstrating its exfoliation, phase transitions, and magnetic properties through experimental and theoretical analysis.

Contribution

It provides the first detailed characterization of MnRhBi3's physical properties, including its cleavability, magnetic phase transitions, and electronic structure, highlighting its suitability for 2D spintronic devices.

Findings

MnRhBi3 is a van der Waals layered material that cleaves easily.

Four phase transitions occur below room temperature, involving antiferromagnetic order.

The material exhibits strong magnetoelastic coupling and complex phase evolution.

Abstract

Cleavable metallic antiferromagnets may be of use for low-dissipation spintronic devices; however, few are currently known. Here we present orthorhombic MnRhBi3 as one such compound and present a thorough study of its physical properties. Exfoliation is demonstrated experimentally, and the cleavage energy and electronic structure are examined by density functional theory calculations. It is concluded that MnRhBi3 is a van der Waals layered material that cleaves easily between neighboring Bi layers, and that the Bi atoms have lone pairs extending into the van der Waals gaps. A series of four phase transitions are observed below room temperature, and neutron diffraction shows that at least two of the transitions involve the formation of antiferromagnetic order. Anomalous thermal expansion points to a crystallographic phase transition and/or strong magnetoelastic coupling. This work reveals a complex phase evolution in MnRhBi3 and establishes this cleavable antiferromagnetic metal as an interesting material for studying the interplay of structure, magnetism, and transport in the bulk and ultrathin limits as well as the role of lone pair electrons in interface chemistry and proximity effects in van der Waals heterostructures.