Studies of iridium-based compounds are at the forefront of solid state physics research. In these materials the electronic configurations are driven by strong spin-orbit coupling. Adding geometric spin frustration may provide a route to realization of the spin-orbit driven quantum spin liquid state. Here we plan to study the frustrated magnetic order Ba3B'Ir2O9 B' = Y, or Sc, combining this data with inelastic neutron scattering to understand the magnetic interactions of this material. To study the frustrated magnetic order from the highly reduced magnetic moment in the Y compound, and to resolve the inhomogenous magnetic state observed in the Sc compound.