  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.
