Magnetic Order and Spin Dynamics in a Hexagonal Rare Earth Manganite

Hexagonal rare earth manganites, \emph{R}MnO$_{3}$ (\emph{R} = Dy, Ho, Er, Tm, Yb, Lu, Y, or Sc), have attracted a great deal of recent attention as magnetoelectric multiferroics as most of these systems are ferroelectric at room temperature and display magnetic order below $T_{N} \approx$ 100 K. This magnetic order can be quite complex, as both the \emph{R} and Mn ions lie on geometrically frustrated triangular lattices. DyMnO$_{3}$ is typically orthorhombic, but can also be grown in the hexagonal phase; Dy$_{0.5}$Y$_{0.5}$MnO$_{3}$ displays the hexagonal phase and is magnetically diluted at the rare earth site. We have used neutron scattering experiments to explore the magnetic structure and spin dynamics of Dy$_{0.5}$Y$_{0.5}$MnO$_{3}$.