We plan to investigate Na2IrO3 samples with a partial substitution of Na by means of a transition metal element (the cases of TM = Co, Ni, Cu and Zn will be considered). The goal is to understand from a microscopic point of view how the magnetically long-range ordered phase realized in Na2IrO3 is pushed towards the limit of glassy magnetism already detected by means of dc magnetometry, ac susceptibility and 23Na NMR. In the samples mentioned above, only the crystalline surroundings of Ir ions are modified and superexchange couplings among the different Ir ions are expected to be modified in turn. Two samples with partial substitution of both Na and Ir (with TM = Fe, Mn) will also be investigated in order to check if and how the spin dilution plays a role in this phenomenon. Both zero-field and longitudinal-field scans are planned for an overall beamtime of 6 days (1 day per sample).