Crystal Structure, Phase Transitions, and Magnetic Properties of Iridium Perovskites Sr2MIrO6 (M = Ni, Zn)

• Published in: Inorganic chemistry 2013-10, Vol.52 (19), p.11013-11022
• Main Authors: Kayser, P, Martínez-Lope, M. J, Alonso, J. A, Retuerto, M, Croft, M, Ignatov, A, Fernández-Díaz, M. T
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic401161d

Double perovskites containing Ir6+/Ir5+ with formula Sr2MIrO6 (M = Ni, Zn) have been synthesized under high oxygen pressure conditions. Their crystal structures have been studied by X-ray and neutron powder diffraction at room temperature (RT) and 2 K. At RT, these oxides crystallize in the monoclinic space group P21/n with unit-cell parameters a ≈ √2a 0, b ≈ √2a 0, and c ≈ 2a 0, and β ≈ 90°. The thermal evolution of the structure of the Ni-containing compound shows the presence of two phase transition in the 373–673 K interval following the sequence P21 /n → I4/m → Fm3̅m. These materials have also been characterized by magnetic measurements, suggesting the onset of antiferromagnetic interactions at T N = 58 and 46 K, for M = Ni, Zn, respectively. X-ray absorption spectroscopy sheds light on the oxidation states of M and Ir ions within these double perovskites.