Long and short range magnetism in the frustrated double perovskite Ba2MnWO6

TL;DR

This study investigates the magnetic properties of Ba2MnWO6, revealing long-range antiferromagnetic order at low temperatures and short-range correlations above the Neel temperature, with detailed insights into magnetic couplings.

Contribution

It provides the first detailed characterization of magnetic interactions and states in Ba2MnWO6, highlighting both long-range and short-range magnetic phenomena in this frustrated double perovskite.

Findings

Long-range antiferromagnetic order at 8 K with frustration index of 8.

Both magnetic coupling constants J1 and J2 are antiferromagnetic and similar in magnitude.

Presence of short-range magnetic correlations above the Neel temperature.

Abstract

The structural and magnetic properties of the face-centered cubic double perovskite Ba2MnWO6 were investigated using neutron powder diffraction, DC-magnetometry, muon spin relaxation and inelastic neutron scattering. Ba2MnWO6 undergoes Type II long-range antiferromagnetic ordering at a Neel temperature of 8(1) K with a frustration index, f = 8. Inelastic neutron scattering was used to identify the magnetic coupling constants J1 and J2, which were found to equal -0.080 meV and -0.076 meV respectively. This indicated that both of the magnetic coupling constants were antiferromagnetic with similar magnitudes, which is in contrast to other known 3d metal double perovskites Ba2MWO6. Above the Neel temperature, muon spin relaxation measurements and inelastic neutron scattering techniques identify a short-range correlated magnetic state that is similar to that observed in the archetypical face-centered cubic lattice antiferromagnet MnO.