  Neutron scattering techniques are used to investigate the crystalline and
magnetic structure of LuFe$_{0.75}$Mn$_{0.25}$O$_{3}$ in bulk polycrystalline
form. We find that the crystalline structure is described by the hexagonal
P6$_{3}$cm space group similar to that of thin-film LuFeO$_{3}$, and that the
system orders antiferromagnetically below T$_{N}$ = 134 K. Inelastic neutron
scattering reveals nearest-neighbor superexchange parameters that are enhanced
relative to LuMnO$_{3}$. The observation of significant diffuse scattering
above T$_{N}$ demonstrates the frustrated nature of the system; comparisons
with similar materials suggest the ground state magnetic configuration is
sensitive to local crystallographic distortions.
