The field of double perovskites is now advancing to three magnetic elements on the A, B and B sites. A series of iridium-based double perovskite compounds, Ln2CoIrO6 (Ln = Eu, Tb, Ho) with three magnetic elements were synthesized as polycrystalline samples. The compounds crystalize in monoclinic structures with the space group P 21/n. Magnetic properties of these hetero-trispin 3d-5d-4f systems were studied by magnetic susceptibility and field dependent magnetization in both DC and pulsed magnetic fields. All these compounds show ferrimagnetic transitions at temperatures TC above 100 K, which are attributable to antiferromagnetic coupling between Co 2+ and Ir 4+ spins. For Eu2CoIrO6, the magnetic properties are similar to those of La2CoIrO6. The Eu 3+ spins show Van Vleck paramagnetism that don't significantly interact with transition-metal cations. By contrast, Tb2CoIrO6 and Ho2CoIrO6 reveal a second transition to antiferromagnetic order below a lower temperature TN . The temperature-induced ferrimagnetic-to-antiferromagnetic phase transition might be explained by a spin-reorientation transition. Moreover, a magnetic-fieldinduced spin-flop transition with a small hysteresis was observed below TN in these two compounds.The magnetic moment of all three compounds do not saturate up to 60 T at low temperatures. Moderate magnetocaloric effect was also observed in all three compounds. Our results should motivate further investigation of the spin configuration on single crystals of these iridium-based double perovskites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.