Relation between structural evolution and effective Ir moments upon applied pressure during synthesis in Ba₃YIr₂O₉

The intensively investigated material class of Iridium oxide based materials provides a variety of new and unknown combinations of magnetic properties with interesting novel or exotic ground states. These Iridate compounds often appear in a perovskite type structure or a related derivative which are very favorable for crystal structure modifications under high pressure. High pressure synthesis therefore can be used to tune or change the magnetic properties appearing under normal pressure. The Iridate Ba₃YIr₂O₉ crystallizes under ambient pressure synthesis in a hexagonal structure and exhibits magnetic ordering below 4 K. A synthesis pressure of 8 GPa advances the material to form a cubic double perovskite structure which is (meta-)stable at ambient pressure. For this high pressure configuration the magnetic ordering is suppressed. We will present our recent results about the systematic high pressure synthesis and characterization of Ba₃YIr₂O₉ samples grown under different growth pressure. The main focus will be on the correlation between structural and magnetic properties depending on the applied pressure during the synthesis process.