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Structural and magnetic properties of hexagonal perovskites La1.2Sr2.7MO7+d (M=Ru,Ir)

T. Goetzfried·A. Reller·S. G. Ebbinghaus
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Abstract

The structures of the new compound La1.2Sr2.7IrO7+d and the recently discovered La1.2Sr2.7RuO7+d have been solved using a combination of X-ray and neutron diffraction. Both compounds crystallize in the trigonal space group R-3m and contain isolated MO6 (M=Ru,Ir) octahedra, which are arranged in well-defined layers. Results of the magnetic susceptibility and XANES measurements show that the transition metal cations are in a pentavalent state. While in La1.2Sr2.7RuO7+d an antiferromagnetic interaction between the Ru5+ ions is found, La1.2Sr2.7IrO7+d shows a very small temperature-independent paramagnetism down to 1.8 K due to the strong spin-orbit coupling characteristic for the 5d element iridium.

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T. Goetzfried, A. Reller, S. G. Ebbinghaus. 2005-04-07. Structural and magnetic properties of hexagonal perovskites La1.2Sr2.7MO7+d (M=Ru,Ir). https://arxiv.org/abs/cond-mat/0504171

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