Osmates in the perovskite-like structure are very topical. For example, recent discoveries include Slater transitions, and "ferroelectric-like" structural transitions. These arise because of structural distortions, geometric frustration, magnetism and strong spin-orbit coupling. We have recently synthesised a new cubic (Fm-3m) double perovskite material Pb2ScOsO6 using a high pressure method. Bulk measurements show at two phase transitions which are both accompanied by modifications of the susceptibility, indicating that the material an antiferromagnetic phase transition and a second phase transition that is either structural in origin or couples the spin and lattice degrees of freedom, presumably owing to the spin-orbit coupled Osmium. We propose to determine the magnetic and crystal structures of Pb2ScOsO6 as a function of temperature between 300 and 10K