Polycrystalline samples of the series of double perovskites Sr2 -xLaxFeIrO6 were synthesized. Their structural, electronic and magnetic properties were investigated by X-ray powder diffraction, Mössbauer spectroscopy, magnetic susceptibility, heat capacity and electrical resistivity experiments. The compounds crystallize in a monoclinic structure and were fitted in space group P21/n, with a significant degree of Fe/Ir cationic disorder. As in Ca2-xLaxFeIrO6 the Sr-based system seems to evolve from an antiferromagnetic ground state for the end members (x=0.0 and x=2.0) to a ferrimagnetic order in the intermediate regions (x∼1). Since Mössbauer spectra indicate that Fe valence remains 3+ with doping, this tendency of change in the nature of the microscopic interaction could be attributed to Ir valence changes, induced by La3+ electrical doping. Upon comparing both Ca and Sr series, Sr2-xLaxFeIrO6 is more structurally homogenous and presents higher magnetization and transition temperatures. Magnetic susceptibility measurements at high temperatures on Sr1.2La0.8FeIrO6 indicate a very high ferrimagnetic Curie temperature TC∼700K. For the Sr 2FeIrO6 compound, electrical resistivity experiments under applied pressure suggest that this material might be a Mott insulator. © 2014 Elsevier Inc.
Bufaiçal, L., Adriano, C., Lora-Serrano, R., Duque, J. G. S., Mendonça-Ferreira, L., Rojas-Ayala, C., Baggio-Saitovitch, E., Bittar, E. M., & Pagliuso, P. G. (2014). Structural, electronic and magnetic properties of the series of double perovskites (Ca, Sr)<inf>2-x</inf><sup>Lax</sup>FeIrO<sup>6</sup> Journal of Solid State Chemistry, 23-29. https://doi.org/10.1016/j.jssc.2014.01.007