Synthesis, Crystal Structures, and Magnetic Properties of Double Perovskites Containing 5d Transition Metals
Loading...
Date
2018-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ohio State University
Abstract
Transition metal oxides containing 5d ions have exhibited many exotic magnetic properties, the underlying mechanisms of which have not yet been fully understood. Many of the unique characteristics of 5d transition metal oxides are thought to be dependent on the strong spin-orbit coupling and the extended d-orbitals. Double perovskites provide a great platform to study the magnetic interactions among 5d transition metal ions because they are amenable to various types of elemental substitutions. For 5d1 and 5d2 electron configurations, magnetic properties such as ferromagnetism, antiferromagnetism, and spin glass have been observed.1 Octahedrally coordinated transition metal ions with a 5d4 configuration should possess a nonmagnetic J=0 ground state, due to the effects of strong spin-orbit coupling. However, recent studies have shown that non-trivial magnetic moments exist in some compounds.2,3 By synthesizing new perovskites containing 5d transition metals, the exotic magnetic properties can be explored. Solid-state synthesis has been performed of targeted stoichiometries of Sr2ZnReO6, which is in a d1 configuration, and Ba2MIrO6 (M= Lu, Fe), Ba3Fe2IrO9, and SrLaM'IrO6 (M'= Zn, Mg, and Ni), which contain ions with a 5d4 configuration. The crystal structures of the products have been studied using X-ray powder diffraction. Sr2ZnReO6 crystallizes in a tetragonal double perovskite structure, Ba2LuIrO6 crystallizes in a cubic double perovskite structure, Ba3Fe1.886Ir1.114O9 and Ba2Fe1.05Ir0.95O6 crystallize in a trigonal structure, and all the other iridates crystallize in a monoclinic double perovskite structure. Magnetic data shows that Ba2LuIrO6, SrLaZnIrO6, and SrLaMgIrO6 are paramagnetic, SrLaNiIrO6 ¬, SrLaNiNbO6, and SrLaNiTaO6 are antiferromagnetic, and Sr2ZnReO6 is ferromagnetic. This study is expected to expand our knowledge of the interesting magnetic phenomena presented by 5d transition metal oxides in different crystal structures and with different B-site cations.
Description
Keywords
magnetism, perovskites, 5d transition metals, crystal structures