Enhancing the Néel temperature in 3d/5d R2NiIrO6 (R=La, Pr and Nd) double perovskites by reducing the R3+ ionic radii. (1st April 2021)

• Record Type: Journal Article
• Authors: Kayser, P.; Muñoz, A.; Martínez, J.L.; Fauth, F.; Fernández-Díaz, M.T.; Alonso, J.A.
• Is Part Of: Acta materialia. Volume 207(2021)
• Publication Date: 2021-04-01
• Subjects: Iridium -- Double perovskites -- 5d transition metals -- Neutron powder diffraction -- La2NiIrO6 -- Pr2NiIrO6 -- Nd2NiIrO6; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2021.116684
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Double perovskites containing Ir 4+ were synthesised by a citrate technique, followed by an annealing treatment in air at 1100 °C. The crystal structure of the three compounds, with formula R2 NiIrO6 (R= La, Pr and Nd), were determined using a combined refinement against neutron powder diffraction (NPD) and synchrotron x-ray powder diffraction (SXRPD) data sets. At room temperature, all the samples were indexed in the space group P21 /n and the monoclinic symmetry remains in the 300 to 1273 K temperature range. Magnetization measurements suggest competitive antiferromagnetic and ferromagnetic interactions, with an unexpected increment of the ordering temperature (TN ) along the series. The magnetic structures of all the samples were defined with the propagation vector k = 0; the Ni 2+ and Ir 4+ moment arrangement, different for each compound, shows a strong dependence on the nature of the rare-earth ion. Graphical abstract: Image, graphical abstract