Antiferromagnetic ground state in the MnGa$_4$ intermetallic compound

TL;DR

This paper demonstrates that MnGa4 exhibits antiferromagnetic order with a transition at 393 K, confirmed by experiments and band-structure calculations, contrasting previous reports of paramagnetism.

Contribution

The study provides the first combined theoretical and experimental evidence of antiferromagnetism in MnGa4, clarifying its magnetic ground state.

Findings

Antiferromagnetic transition at 393 K

Magnetic moments aligned along [111] direction

Magnetic moment of 0.80 μB at 1.5 K

Abstract

Magnetism of the binary intermetallic compound MnGa$_4$ is re-investigated. Band-structure calculations predict antiferromagnetic behavior in contrast to Pauli paramagnetism reported previously. Magnetic susceptibility measurements on single crystals indeed reveal an antiferromagnetic transition at $T_N=393$ K. Neutron powder diffraction and $^{69,71}$Ga nuclear quadrupole resonance spectroscopy show collinear antiferromagnetic order with magnetic moments alligned along the [111] direction of the cubic unit cell. The magnetic moment of 0.80(3)$\mu_B$ at 1.5 K extracted from the neutron data is in good agreement with the band-structure results.