We propose to investigate the roles of the spin-orbit interaction and geometrical frustration in stabilising a quantum spin liquid phase (QSL) in some iridate systems. µSR is a sensitive probe of the possible exotic ground states in the iridates. To further understand the systematics of the QSL phase we plan to investigate the glassy ordering of isostructural materials with either reduced spin-orbit interactions or a system with classical spins. Our results are expected to provide insight into the magnetism of iridate systems beyond the Heisenberg spin model.