We propose to obtain the detailed temperature dependent diffusion characteristics for diamagnetic muonium defect centres, assumed to be a 'bare' muon, in selected members of the II-IV-V2 class of chalcopyrite structured semiconductors. These materials are strong candidates for spintronics applications, showing ferromagnetism with Tc above 300 K when doped with Mn. MuSR can provide detailed information on the microscopic distribution of local magnetic fields. However, claims of a very uniform distribution of internal fields, e.g. in Mn-doped CdGeAs2, rely on an assumption that the muon probe remains stationary. Results of this project will yield the motional properties of the muon probe in undoped II-VI-V2 host materials, which is critical to properly interpreting results of MuSR data on the Mn doped chalcopyrites, as well as characterizing hydrogen behaviour in these compounds.